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Alibeygi Beni A.,Islamic Azad University at Shoshtar | Alibeygi Beni A.,National Iranian Oil Company | Malekzadeh P.,Persian Gulf University
Composite Structures | Year: 2012

The free vibration of orthotropic non-prismatic skew nanoplate based on the first-order shear deformation theory (FSDT) in conjunction with Eringen's nonlocal elasticity theory is presented. As a simple, accurate and low computational effort numerical method, the differential quadrature method (DQM) is employed to solve the related differential equations. For this purpose, after deriving the equations of motion and the related boundary conditions, they are transformed from skewed physical domain to rectangular computational domain of DQM and accordingly discretized. After validating the formulation and method of solution, the effects of nonlocal parameter in combination with geometrical parameters and boundary conditions on the natural frequencies of the orthotropic skew nanoplates are investigated. © 2012 Elsevier Ltd.

Saeedipour S.,Islamic Azad University at Shoshtar
Proceedings of the National Academy of Sciences India Section B - Biological Sciences | Year: 2013

The present work investigated the effects of endogenous abscisic acid (ABA) and proline contents related to yield in two wheat (Triticum aestivum L.) cultivars, Marvdasht and Zagros, sensitive and tolerant to terminal season drought, respectively, grown in pots under well watered and water-stressed condition starting from anthesis until maturity. Water stress resulted in marked increase in the ABA content of both cultivars. However, the absolute of ABA concentration in tolerant cultivar was more than that of sensitive cultivars. Water stress caused to elevate the leaf proline content of the drought-tolerant that, seemingly led to alleviate the deleterious effect of water stress whereas, a slight increment in proline levels was observed at the end of grain development in drought sensitive cv. The effect of drought on grain yield was primarily due to the significant reduction in grain weight, particularly in drought-sensitive cultivars. The protective effect of both ABA and proline was more pronounced in Zagros cv. that exhibited higher grain yield under water deficit conditions. © 2012 The National Academy of Sciences, India.

Kahyaei A.,Islamic Azad University at Shoshtar
Research Journal of Applied Sciences, Engineering and Technology | Year: 2011

The Interline Power Flow Controller (IPFC) is one of the latest generation Flexible AC Transmission Systems (FACTS) controller used to control power flows of multiple transmission lines. The aim of this paper is investigation of the effect of location of IPFC on profile of voltage and real and reactive power flow in transmission lines in power system. This model is incorporated in Newton-Raphson (NR) power flow algorithm to study the power flow control in transmission lines in which IPFC is placed. A program in MATLAB/SIMULINK has been written in order to extend conventional NR algorithm based on this model. Numerical results are carried out on a standard power system. The results without and with IPFC for various locations are compared in terms of voltages, active and reactive power flows to demonstrate the performance of the IPFC model. © 2011 Maxwell Scientific Organization.

Kahyaei A.,Islamic Azad University at Shoshtar
Research Journal of Applied Sciences, Engineering and Technology | Year: 2011

This research studies the effect of location of Unified Power Flow Controller (UPFC) on power system. In this study the several case studies including various points for installing UPFC on power system are considered and results of profile of voltage at all of buses of system is obtained. The active and reactive of all transmission lines of power system following installing UPFC at various points of system is discussed and results are analyzed. The encouragement to the construction of HV lines, the amount of power transmission/km on HV line and the amount of power transaction as seen from economic side is much responsible for concern towards congestion in power system. The solution is the use of FACTS devices especially the use of UPFC. In this research the study of UPFC with its various candied locations for installing on power system is understood. Second, the operation of control system used in its converters is also studied. Finally by help of modeling of a power system in MATLAB/SIMULINK, and by installing UPFC in transmission link, its use as power flow controller and voltage injection is seen. Conclusion is made on different results to see the benefit of UPFC in power system. © 2011 Maxwell Scientific Organization.

Moeinifar S.,Islamic Azad University at Shoshtar | Kokabi A.H.,Sharif University of Technology | Hosseini H.R.M.,Sharif University of Technology
Journal of Materials Processing Technology | Year: 2011

The influence of thermal cycles on the properties of the coarse grained heat affected zone in X80 microalloyed steel has been investigated. The thermal simulated involved heating the X80 steel specimens to the peak temperature of 1400 °C, with different cooling rates. The four-wire tandem submerged arc welding process, with different heat input values, was used to generate a welded microstructure. The martensite/austenite constituent appeared in the microstructure of the heat affected zone region for all the specimens along the prior-austenite grain boundaries and between the bainitic ferrite laths. The blocky-like and stringer martensite/austenite morphology were observed in the heat affected zone region. The fractional area of M/A particles due to different cooling rate was the main factor in increasing of the hardness values in the coarse grained heat affected zone. The Charpy absorbed energy of specimens was assessed using Charpy impact testing at -50 °C. The martensite/austenite constituent's size such as mean diameter and length are important factors influencing Charpy impact properties of coarse grained heat affected zone. The micro crack nucleation may occur from M/A particles at the intersection of prior-austenite grain boundaries. Similar crack initiation sites and growth mechanism were investigated for specimens welded with different heat input values. © 2010 Elsevier B.V. All rights reserved.

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