Islamic Azad University at Miyaneh
Miyaneh, Iran

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Esrafili M.D.,Islamic Azad University at Maragheh | Vakili M.,Islamic Azad University at Miyaneh
Molecular Physics | Year: 2017

Ab initio calculations at the MP2/aug-cc-pVTZ level of theory are performed to investigate the effect of hydrogen-bonding cooperativity on the strength and bonding properties of σ-hole interaction in linear FCl⋅⋅⋅(NCH)n =2 – 5, FHS⋅⋅⋅(NCH)n =2 – 5, FH2P⋅⋅⋅(NCH)n =2 – 5 and FH3Si⋅⋅⋅(NCH)n =2 – 5 clusters. It is found that the cooperative effects in the hydrogen-bonding tend to strengthen the σ-hole interaction. However, these effects are almost saturated in the larger clusters (n > 5). For a given cluster, the amount of bond contraction in FCl⋅⋅⋅(NCH)n is more important than other systems. A nice linear relationship is found between the σ-hole bond energies and absolute 15N chemical shieldings or spin–spin coupling constants across the σ-hole bond. © 2017 Informa UK Limited, trading as Taylor & Francis Group.

Kisi O.,Canik Basari University | Kisi O.,Erciyes University | Ali Baba A.P.,Islamic Azad University at Miyaneh | Shiri J.,University of Tabriz
Journal of Irrigation and Drainage Engineering | Year: 2012

Estimation of daily pan evaporation values is of most importance in water resource system management and planning. This paper presents a study aimed at developing generalized neurofuzzy (GNF)-based evaporation models corresponding to Penman, Stephens-Stewart (SS), and Griffiths methods. A GNF model was also made by using temperature as the sole input parameter to evaluate the application of single-input temperature-based models for estimating the evaporation values. In the first part of the study, neurofuzzy (NF) evaporation models were developed and compared with Penman, SS, and Griffiths models for three weather stations located in Arizona, USA. Five-parameter NF models were generally found to be better than the Penman, SS, and Griffiths models. The NF models were used for estimating evaporations at the Tucson station by using the data from the Phoenix and Flagstaff stations in the second part of the study. It was found that NF models can be successfully used in cross-station applications. In the third part of the study, the GNF models were obtained by calibrating and using the pooled data from the Phoenix, Flagstaff, and Tucson stations located in Arizona and were tested using the data from weather stations in Albuquerque, NM; Tucumcari, NM; Cedar City, UT; and Ahwaz, Iran). Generalized SS and Griffiths models were also obtained and compared with GNF models. The comparison of the results revealed that the GNF models performed better than the Penman generalized SS, and Griffiths models. However, the generalized SS and Penman models were found to be better than the GNF model for the Ahwaz station. © 2012 American Society of Civil Engineers.

Faieghi M.,Islamic Azad University at Miyaneh | Jalali A.,Iran University of Science and Technology | Mashhadi S.K.E.D.M.,Iran University of Science and Technology
ISA Transactions | Year: 2014

The cruise control problem of high speed trains in the presence of unknown parameters and external disturbances is considered. In particular a Lyapunov-based robust adaptive controller is presented to achieve asymptotic tracking and disturbance rejection. The system under consideration is nonlinear, MIMO and non-minimum phase. To deal with the limitations arising from the unstable zero-dynamics we do an output redefinition such that the zero-dynamics with respect to new outputs becomes stable. Rigorous stability analyses are presented which establish the boundedness of all the internal states and simultaneously asymptotic stability of the tracking error dynamics. The results are presented for two common configurations of high speed trains, i.e. the DD and PPD designs, based on the multi-body model and are verified by several numerical simulations. © 2013 ISA.

Faieghi M.,Islamic Azad University at Miyaneh | Kuntanapreeda S.,King Mongkut's University of Technology Bangkok | Delavari H.,Hamedan University of Technology | Baleanu D.,Cankaya University | Baleanu D.,Romanian Space Science Institute
Nonlinear Dynamics | Year: 2013

Based on the theory of stabilization of fractional-order LTI interval systems, a simple controller for stabilization of a class of fractional-order chaotic systems is proposed in this paper. We consider the structure of the chaotic systems as fractional-order LTI interval systems due to the limited amplitude of chaotic trajectories. We introduce a simple feedback controller for the interval system and then, based on a recently established theorem for stabilization of interval systems, we reach to a linear matrix inequality (LMI) problem. Solving the LMI yields an appropriate decoupling feedback control law which suffices to bring the chaotic trajectories to the origin. Several illustrative examples are given which show the effectiveness of the method. © 2013 Springer Science+Business Media Dordrecht.

Nemati A.,Islamic Azad University at Miyaneh | Fathi V.,Islamic Azad University at Pārsābād | Barzegar R.,Islamic Azad University at Pārsābād | Khalilarya S.,Urmia University
International Journal of Hydrogen Energy | Year: 2013

In the present article, a Computational Fluid Dynamics (CFD) method and a home-made FORTRAN code have been utilized to investigate the effects of injection timing under various equivalence ratios on the first and second laws of thermodynamics terms in a hydrogen fueled Direct Injection Spark Ignition (DISI) engine. The results show a good agreement with the experimental data. Exergy terms such as exergy transfer with work, exergy transfer with heat, exergy transfer with exhaust gas and fuel chemical exergy were computed based on principles of the second law. Also Entropy generation per cycle is calculated. Special attentions are given to recognize and quantify the irreversibility of combustion process basing on the different injection timings and equivalence ratios. The obtained results indicated that combustion irreversibilities and exhaust gas availability are more affected by varying the equivalence ratio and amount of fuel availability that transfers to environment with exhaust gases increased by increasing the equivalence ratio. Varying the equivalence ratio had different effect on the accumulated work availability reduced to fuel availability at the late and early injection strategies. Also, entropy generation reduced by retarding the hydrogen injection timing and decreasing the equivalence ratio. Changing in injection timing has its maximum effect on Φ = 0.6 equivalence ratio.Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights.

Faieghi M.R.,Islamic Azad University at Miyaneh | Delavari H.,Hamedan University of Technology | Baleanu D.,Cankaya University | Baleanu D.,Romanian Space Science Institute
JVC/Journal of Vibration and Control | Year: 2012

Robust control of fractional-order Liu system is addressed in this paper. The proposed approach relies on sliding mode control being established on a novel fractional-order integral type sliding surface. Theoretically, based on classical Lyapunov stability theorem, it has been shown that under suitable conditions, the proposed controller guarantees the system's stability. Further, it is shown that the method presented is capable for both commensurate and incommensurate systems. In order to reduce the chattering effect, a fuzzy logic controller is employed. Numerical simulations verify these results. © The Author(s) 2011 Reprints and permissions:

Faieghi M.R.,Islamic Azad University at Miyaneh | Delavari H.,Hamedan University of Technology | Baleanu D.,Cankaya University | Baleanu D.,King Abdulaziz University | Baleanu D.,Romanian Space Science Institute
Computers and Mathematics with Applications | Year: 2013

We consider a class of fractional-order chaotic systems which undergoes unknown perturbations. We revisit the problem of sliding mode controller design for robust stabilization of chaotic systems using one control input. In the recent works, it was assumed that one of the system equations are perturbed by uncertainties. For this case we show that the sliding mode dynamics are globally stable which is not addressed so far. Next, we allow that all the system's equations depend on uncertain terms and provide a theoretical justification for applicability of the existing design. We also determine the least amount of precise information about the chaotic system that is needed to design the controller.

Asadpour J.,Islamic Azad University at Miyaneh
Optoelectronics and Advanced Materials, Rapid Communications | Year: 2011

Let G=(V,E) be a graph, where V is a non-empty set of vertices and E is a set of edges. Suppose that G be a graph, e=uvεE(G), d(u) be degree of vertex u. In this paper we compute Zagreb, Randic ́ and ABC indices Polynomial of TUC4C8(S), TUC4C8(R) nanotube and V-Phenylenic nanotorus.

Mardi K M.,Urmia University | Khalilarya S.,Urmia University | Nemati A.,Islamic Azad University at Miyaneh
Energy Conversion and Management | Year: 2014

Alternative fuels are mostly extracted from renewable resources, and their emission levels can be lower than those of traditional fossil-based fuels. A computational fluid dynamics (CFD) method is utilized to investigate the effects of exhaust gas recirculation (EGR) and initial charge pressure on the emissions and performance of a SI engine. The engine is fueled separately by gasoline and some of potential alternative fuels including hydrogen, propane, methane, ethanol and methanol. The results of simulation are compared to the experimental data. In all validation cases, experimental and numerical results were observed to have good agreement with each other. The calculations are carried out for EGR ratios between 0% and 20% and four cases of initial pressure have been mentioned: Pin = 1, 1.2, 1.4, 1.6 bar. The effect of EGR on NO x emission of methane is more than other fuels and its effect on IMEP of hydrogen is less than other fuels. From the viewpoints of emission and power, 10% of EGR seems to be the most desirable amount. The most noticeable effect of supercharging is on gasoline unlike hydrogen, which seems to be affected the least. The comparison of results shows that hydrogen due to its high heating value and burning without producing any carbon-based compounds such as HC, CO and CO2 is an ideal alternative fuel compared to the other fuels. © 2014 Elsevier Ltd. All rights reserved.

Vessally E.,Islamic Azad University at Miyaneh
Russian Journal of Physical Chemistry A | Year: 2011

Energy differences, ΔX s-t (X = E, H, and G) (ΔX s-t = X(singlet) - X(triplet)) between singlet (s) and triplet (t) states of C12H8M were calculated at B3LYP/6-311+G*. The DFT calculations indicated that the ΔG s-t between singlet (s) and triplet (t) states of C12H8M were increased from M = C to M = Pb. The ΔG s-t of C12H8M was compared with its analogue C4H4M through replacement of heavy atoms from M = C to M = Pb. Configurations of the electrons in orbitals (σ2 or π2) for the singlet state of C 12H8M were discussed. © 2011 Pleiades Publishing, Ltd.

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