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Davarani R.Z.,Graduate University of Advanced Technology | Ghazi R.,Ferdowsi University of Mashhad
Journal of Electrical Systems

Power system stability enhancement via optimal simultaneous coordinated design of a power system stabilizer (PSS) and a thyristor-controlled series capacitor (TCSC) for electric power systems oscillations damping is investigated in this paper. A SMIB system equipped with PSS and TCSC controllers is considered in this study. Although these controllers are used for stabilization of power system oscillations but the system must preserve its stability when subjected to sever disturbances. Therefore, the overall stability of the system should be considered. To do so, in the present paper the problem of controllers design is formulated as a multi objective optimization problem. Then the multi objective genetic algorithm (MOGA) is explored to solve this optimization problem. Pareto method type of selection is used in the present MOGA approach. © JES 2013. Source

Noori H.R.,Islamic Azad University at Kerman | Jomehzadeh E.,Graduate University of Advanced Technology
Mechanics and Industry

In this paper, a Levy-type solution based on the modified couple stress theory is developed to study the buckling behaviors of micro-plates. Based on this theory, length scale parameter is considered to capture the size effect of rectangular micro-plates. Minimum potential energy and adjacent-equilibrium criteria are exploited to obtain the stability equations and corresponding boundary conditions. Different boundary conditions with two opposite edges simply supported and arbitrary boundary conditions along the other edges are considered. To illustrate the new model, both uniaxial and biaxial loads are applied and the critical buckling loads are defined for over a wide range of thickness, different length scale parameters and various boundary conditions. To show the accuracy of the formulations, present results are compared with available results in literature for specific cases and a very good agreement is observed. Results reveal that the critical buckling load increases as the length scale parameter increases especially when the thickness of the micro-plates becomes in order of length scale parameter and this effect is more significant for free boundary condition. © 2014 AFM, EDP Sciences. Source

Roohollahi E.,Shahid Bahonar University of Kerman | Mehrabian M.A.,Shahid Bahonar University of Kerman | Abdolzadeh M.,Graduate University of Advanced Technology
Energy and Buildings

In this study, the solar energy gain on 3-D geometries and the amounts of energy output from photovoltaic panels fixed on selected geometries were determined using the radiation data collected by the Iranian Meteorological Organization on a horizontal surface. The results can be used in designing solar houses, street and traffic lights, and rail transport systems. The K-T model was used to calculate the daily average solar radiation intensity; the solar radiation data on a horizontal surface in Kerman was used as input in the above mentioned model. The solar energy on 3-D geometries was calculated in different directions throughout the year. Finally, the geometries were compared with each other in terms of solar energy gain in different months of the year. The results show that the solar energy gain on selected geometries in hot season of the year prevails in east-west direction. © 2013 Elsevier B.V. All rights reserved. Source

Marandi S.M.,Shahid Bahonar University of Kerman | Anvar M.,Graduate University of Advanced Technology | Bahrami M.,Shahid Bahonar University of Kerman
Computers and Geotechnics

Uncertainty in safety factor (FS) of slope stability is a main subject in geotechnical engineering. Uncertainties are associated with shear strength parameters of the soil, their complex nature, numerical analysis methods, etc. The main aim of this research was to improve the model used by other researchers for determination of FS of embankments built on stone column improved soft soils, and compare the results with what was found in literature using α-cut fuzzy technique (FAC). The results showed that the highest and lowest uncertainty occurred at equivalent area with existence of underground water, and for single stone column with no underground water respectively. A reduction factor proposed to amend the FS calculated using the equivalent area method. In the equivalent area model, the equivalent parameters were used. This contribution might have real and more precise behavior in comparison with what was suggested by other researchers in literature. In addition, with applying of membership functions, the height of embankment had the most effect on the values of FS obtained using finite element (FE) and finite difference (FD) methods. © 2016 Elsevier Ltd. Source

Eren T.,Pamukkale University | Atar N.,Pamukkale University | Yola M.L.,Sinop University | Karimi-Maleh H.,Graduate University of Advanced Technology
Food Chemistry

Lovastatin (LOV) is a statin, used to lower cholesterol which has been found as a hypolipidemic agent in commercial red yeast rice. In present study, a sensitive molecular imprinted quartz crystal microbalance (QCM) sensor was prepared by fabricating a self-assembling monolayer formation of allylmercaptane on QCM chip surface for selective determination of lovastatin (LOV) in red yeast rice. To prepare molecular imprinted quartz crystal microbalance (QCM) nanosensor, LOV imprinted poly(2-hydroxyethyl methacrylate-methacryloylamidoaspartic acid) [p(HEMA-MAAsp)] nanofilm was attached on the modified gold surface of QCM chip. The non-modified and improved surfaces were characterized by using contact angle, atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectroscopy. The imprinted QCM sensor was validated according to the ICH guideline (International Conference on Harmonisation). The linearity range was obtained as 0.10-1.25 nM. The detection limit of the prepared material was calculated as 0.030 nM. The developed QCM nanosensor was successfully used to examine red yeast rice. Furthermore, the stability and repeatability of the prepared QCM nanosensor were studied. The spectacular long-term stability and repeatability of the prepared LOV-imprinted QCM nanosensor make them intriguing for use in QCM sensors. © 2015 Elsevier Ltd. All rights reserved. Source

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