Semnan, Iran
Semnan, Iran

Semnan University is a prestigious university in Iran located in the city of Semnan, Iran, about 240 km east of Tehran.The university has over 15,000 students, 60 undergraduate programs, 95 graduate , and 55 PhD programs. It has 25 faculties, 2 colleges, 2 institutes, 9 research groups, one Science and Technology Park, one Advanced Technologies Incubator Centre. The initial nucleus of Semnan University was formed in 1975 with the establishment of Semnan Higher Education Center. It launched its activities with 580 students to study in seven programs with an area of 5000 square meters.After the victory of the Islamic Revolution, extensive and fundamental changes were implemented at the Centre. In 1989, Semnan Higher Education Centre started its work under new title of Semnan Higher Education Complex while it enhanced its Electronic & Civil programs to a Bachelor level. With opening of the faculty of engineering, faculty of teacher training and faculty of veterinary medicine, Semnan Higher Education Complex changed its status to Semnan University in 1994.Semnan University has so expanded to include four campuses: 1. Technical campus2. Basic science campus3. Human science campus4. New Science and Technology campusThe university has 608 full-time academic members. It is situated in the Northeast part of the Semnan city with an area of 800 hectares. Libraries, computer centres, sports halls, restaurants, coffee shop and several dormitories are other facilities of the university. Since Semnan University is relatively young and newly established it is still under expansion and construction. Wikipedia.

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Najibi A.,Semnan University
International Journal of Pressure Vessels and Piping | Year: 2017

The material composition evaluation in functionally graded materials is the main concern of a designer to enhance the appropriate functionality of these materials to adopt them in their applications. In this study, new 2D-FGM material model based on the Mori-Tanaka scheme and third order transition function was developed for a thick hollow cylinder with finite length. The cylinder is subjected to the internal or external non-uniform pressure and also the finite element method was performed to analyse axisymmetric elastic stress. It has been demonstrated that the values of the stresses evaluated from external pressure loading were higher than the internal pressure loading ones. Subsequently, the values of Normalized Effective Stress (NES) vs. metallic volume fraction along the horizontal centre line have not been changed significantly by the variation of nz. In addition, the values of the NES which evaluated on the centre point of cylinder wall have been increased by increasing of the nr. Finally, it has been shown in details that the lowest value of the maximum NES was related to the nr = 20 and nz = 0.1 for both internal and external pressure loading. It means that the ceramic 2 (Si3N4) rich cylinder wall has the lowest value of maximum NES. © 2017 Elsevier Ltd

In this article, thermo-mechanical fatigue behaviors in light alloys have been investigated to find the effect of heat treatments. For this objective, thermo-mechanical fatigue tests were performed on the A356.0 aluminum alloy and the AZE911 magnesium alloy, with and without typical T6 heat treatments. Obtained results demonstrated no significant difference in thermo-mechanical fatigue lifetime of the A356.0 alloy between non-heat-treated and heat-treated test specimens at 250 °C of the maximum temperature, which was attributed to the over-ageing phenomenon. As a consequence, this low effect showed that the heat treatment could be eliminated for cylinder heads. However, the thermo-mechanical fatigue lifetime of the AZE911 alloy was significantly affected by the heat treatment. The explanation for the mentioned behavior could be found in the material micro-structure, which was affected by dissolving the brittle intermetallic phase in the matrix of the AZE911 alloy. However, the magnesium alloy still requires more improvements in the fatigue lifetime for a possible substitution in cylinder heads. Continuum damage behaviors showed that higher damage values occurred in the aluminum alloy, in comparison to the magnesium alloy, both for heat-treated and non-heat-treated specimens. © 2016 Elsevier Ltd

Goharipour M.,Semnan University | Mehraban H.,Semnan University
Physical Review D | Year: 2017

Prompt photon production is known as a powerful tool for testing perturbative QCD predictions and also the validity of parton densities in the nucleon and nuclei, especially of the gluon. In this work, we have performed a detailed study on this subject, focusing on the isolated prompt photon production in p-Pb collisions at forward rapidity at the LHC. The impact of input nuclear modifications obtained from different global analyses by various groups on several quantities has been investigated to estimate the order of magnitude of the difference between their predictions. We have also studied in detail the theoretical uncertainties in the results due to various sources. We found that there is a remarkable difference between the predictions from the nCTEQ15 and other groups in all ranges of photon transverse momentum pTγ. Their differences become more explicit in the calculation of the nuclear modification ratio and also the yield asymmetry between the forward and backward rapidities rather than single differential cross sections. We emphasize that future measurements with ALICE will be very useful, not only for decreasing the uncertainty of the gluon nuclear modification, but also to accurately determine its central values, especially in the shadowing region. © 2017 American Physical Society.

Amjady N.,Semnan University | Vahidinasab V.,University of Tehran
Energy Conversion and Management | Year: 2013

In this paper, a new security-constrained self-scheduling framework incorporating the transmission flow limits in both steady state conditions and post-contingent states is presented to produce efficient bidding strategy for generation companies (GENCOs) in day-ahead electricity markets. Moreover, the proposed framework takes into account the uncertainty of the predicted market prices and models the risk and profit tradeoff of a GENCO based on an efficient multi-objective model. Furthermore, unit commitment and inter-temporal constraints of generators are considered in the suggested model converting it to a mixed-integer programming (MIP) optimization problem. Sensitivity of the proposed framework with respect to both the level of the market prices and adopted risk level is also evaluated in the paper. Simulation results are presented on the IEEE 30-bus and IEEE 118-bus test systems illustrating the performance of the proposed self-scheduling model. © 2012 Elsevier Ltd. All rights reserved.

In present study, a refined nth-order shear deformation theory is proposed, formulated and validated for a variety of numerical examples of functionally graded (FG) plates resting on elastic foundation for the mechanical and thermal buckling responses. The present refined nth-order shear deformation theory is based on assumption that the in-plane and transverse displacements consist of bending and shear components, in which the bending components do not contribute toward shear forces and, likewise, the shear components do not contribute toward bending moments. The most interesting feature of this theory is that it accounts for a parabolic variation of the transverse shear strains across the thickness and satisfies the zero traction boundary conditions on the top and bottom surfaces of the plate without using shear correction factors. Governing equations are derived from the principle of minimum total potential energy. A Navier type closed form solution methodology is also proposed for simply supported FG plates resting on elastic foundation which provides accurate solution. The accuracy of the present theory is verified by comparing the obtained results with those predicted by classical plate theory (CPT), first-order shear deformation theory (FSDT), higher-order shear deformation theory (HSDT) and refined plate theory (RPT). Moreover, results show that the present theory can achieve the same accuracy of the existing higher-order shear deformation theories which have more number of unknowns. © 2014 Elsevier Ltd. All rights reserved.

Yousefpour M.,Semnan University | Rahimi A.,Semnan University
Materials and Design | Year: 2014

In this study, Nano particles were co-deposited with chromium from a hexavalent chromium bath by the conventional electrodeposition onto steel substrate as a cathode. The main goal of this work is to improve the wear and corrosion resistance, microhardness, coefficient of friction and select the best coating condition to satisfy these parameters using combined Analytic Hierarchy Process (AHP) - Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method. The dependence of the mentioned parameters was investigated in relation to the Al2O3, TiO2, SiO2 concentration in bath and particle size and it was found that the best tribological behavior improves by decreasing the particle size and increasing the particles concentration in the bath up to 10g/l. AHP-TOPSIS method led to choose the Cr-Al2O3 nanocomposite coating achieved at 10g/l Al2O3 content with mean particle size of 10nm as the preferred alternative which is in good accordance with empirical findings. © 2013 Elsevier Ltd.

Oghbaei M.,Semnan University | Mirzaee O.,Semnan University
Journal of Alloys and Compounds | Year: 2010

Microwave sintering has emerged in recent years as a new method for sintering a variety of materials that has shown significant advantages against conventional sintering procedures. This review article first provides a summary of fundamental theoretical aspects of microwave and microwave hybrid sintering, and then advantages of microwave sintering against conventional methods are described. At the end, some applications of microwave sintering are mentioned which so far have manifested the advantages of this novel method. © 2010 Elsevier B.V. All rights reserved.

Moravej Z.,Semnan University | Akhlaghi A.,Semnan University
International Journal of Electrical Power and Energy Systems | Year: 2013

This paper presents a novel approach based on cuckoo search (CS) which is applied for optimal distributed generation (DG) allocation to improve voltage profile and reduce power loss of the distribution network. The voltage profile which is the main criterion for power quality improvement is indicated by two indices: voltage deviations from the target value which must be minimized and voltage variations from the initial network without DG which must be maximized. The CS was inspired by the obligate brood parasitism of some cuckoo species by putting their eggs in the nests of other species. Some host birds can engage direct contest with the infringing cuckoos. For example, if a host bird detects the eggs are not their own, it will either throw these alien eggs away. The CS has been compared with other evolutionary algorithms such as genetic algorithm (GA) and particle swarm optimization (PSO) and different cases have been investigated for indicating the applicability of the proposed algorithm. The results indicate the better performance of CS compared with other methods due to the fewer parameters which must be well-tuned in this method. In addition, in this method the convergence rate is not sensitive to the parameters used, so the fine adjustment is not needed for any given problems. © 2012 Elsevier Ltd. All rights reserved.

Amjady N.,Semnan University | Reza Ansari M.,Semnan University
Energy Conversion and Management | Year: 2013

This paper presents a new approach based on Benders decomposition (BD) to solve hydrothermal unit commitment problem with AC power flow and security constraints. The proposed method decomposes the problem into a master problem and two sets of sub-problems. The master problem applies integer programming method to solve unit commitment (UC) while the sub-problems apply nonlinear programming solution method to determine economic dispatch for each time period. If one sub-problem of the first set becomes infeasible, the corresponding sub-problem of the second set is called. Moreover, strong Benders cuts are proposed that reduce the number of iterations and CPU time of the Benders decomposition method. All constraints of the hydrothermal unit commitment problem can be completely satisfied with zero penalty terms by the proposed solution method. The methodology is tested on the 9-bus and IEEE 118-bus test systems. The obtained results confirm the validity of the developed approach. © 2012 Elsevier Ltd. All rights reserved.

Aluminum matrix composites (AMCs) reinforced with particles are of the most widely applied commercial materials. Among the numerous methods for AMCs production, the powder metallurgy is the most attractive technique since it gives good mechanical properties and is an inexpensive process. In the last decade, the Al-SiC composites have introduced most wide spread applications and hold the greatest promise for future growth. In present study, a comparison was carried out between technique for order preference by similarity to ideal solution (TOPSIS) and preference selection index (PSI) materials selection methods for determining a desirable combination of strength and workability in Al-SiC powder metallurgy composite. Selection of an Al-SiC composite with highest strength and workability is a MADM problem where some criteria must be considered in decision making among a set of available alternatives. Weights of each criterion were determined by using an analytic hierarchy process (AHP) method in TOPSIS method. The obtained results represented that the PSI method could be successfully applied to select best alternative without assigning the relative importance between attributes and it could be appropriately replaced to general materials selection methods such as TOPSIS method. Empirical findings in this study showed that both TOPSIS and PSI methods led to the choice of Al-5%SiC composite with SiC particle size of 16. μm and relative density of 90% milled for 12. h as the preferred alternative. © 2013 Elsevier Ltd.

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