Ahvaz, Iran

Shahid Chamran University of Ahvaz is a major Iranian university in Ahvaz, Khuzestan, Iran.By the ISC ranking ,Shahid Chamran University of Ahvaz is 13th largest and top univesity in Iran.<http://ur.isc.gov.ir>.SCU University is considered one of Iran's "Grade A" universities by Iranian Ministry of Science.The campus today has 276 acres and houses 13 colleges. In 2010, 4798 students were enrolled. Wikipedia.

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Asadi S.,Shiraz University | Moore F.,Shiraz University | Zarasvandi A.,Shahid Chamran University
Earth-Science Reviews | Year: 2014

The Kerman Cenozoic magmatic arc (KCMA), located on the southeast of the Central Iranian volcano-plutonic belt, hosts some world class porphyry copper deposits. Temporally, the deposits overlap with the Alpine-Himalayan collision, which has some key implications for the existence or lack of copper mineralization during orogenic arc system development. Transition from normal calc-alkaline arc magmatism in the Eocene-Oligocene (Jebal Barez-type) to adakite-like calc-alkaline magmatism (Kuh Panj-type) in the mid-late Miocene-Pliocene reflects the onset of collision between the Afro-Arabian and Eurasian plates in the Kerman Cenozoic arc segment. The aim of this review is to determine the role of Cenozoic magmatic events in the development of economic to sub-economic porphyry copper mineralization in the southeastern parts of the Central Iranian volcano-plutonic belt. In order to discriminate between the various magmatic systems (KCMA) involved in that development, a geochemical investigation is carried out using samples collected from all important deposits in the region (this study) and previous published data by earlier researchers in this region. It is evident from these data that the collisional Neogene Kuh Panj porphyry suite is distinctly more evolved than the pre-collisional Eocene-Oligocene Jebal Barez granitoids, with relative enrichments in incompatible elements, Sr/Y (>55), and La/Yb (>20), slightly positive Eu anomalies (Eun/Eu*≈1), and depletions in HFSE, with [La/Sm]n≈4.6-6.6 and [Dy/Yb]n≈1.0-2.0, and relatively non-radiogenic Sr isotope signatures (87Sr/86Sr=0.7042-0.7047). In contrast, Jebal Barez granitoids exhibit low Sr/Y (<21) and La/Yb (<9) ratios, negative Eu anomalies (Eun/Eu*≈0.5), and enrichment in HFSE and radiogenic Sr isotope signatures (87Sr/86Sr=0.7053-0.7075). The temporal along with lithogeochemical and isotopic changes, reflect a progressive transfer of the melting zone from the juvenile mafic lower crust (garnet-free amphibolite) into garnet-amphibolite. This transfer is the result of compressional stress along with tectonic shortening during Eocene-Oligocene (~30-35km crustal thickness) to mid-late Miocene (~45-55km thick or 12-15kbar). The absence of volcanism, under prevailing compressional conditions (mid-late Miocene-Pliocene), prevented the escape of SO2 from the adakite-like, sulfur-rich, highly oxidized magmas ("closed porphyry systems"), which allowed formation of several world-class to giant mineral deposits. Volcanic activity during formation of the subvolcanic Eocene-Oligocene porphyries allowed development of "open porphyry systems", which, in turn to partial outgassing of volatiles, and therefore, far less significant mineral deposits. © 2014 Elsevier B.V.

Ranjbar K.,Shahid Chamran University
Materials and Design | Year: 2010

Failure of a tubular heat exchanger made up of copper based alloys in a steam power plant was investigated. Tubes were made initially from yellow brass, and there after replaced by Cu-5Ni alloys. Circulating water from cooling tower was used as coolant, to condense the hot steam inside the steel shell. The velocity of cooling water was found to be very low, causing accumulation of deposits, reduction of diameter and some times complete blockage of tubes. The causes of failure were investigated performing various tests such as chemical analysis, XRD, optical, and SEM examination. Study revealed that tube material suffering from extensive dealloying and impingement attack. © 2009 Elsevier Ltd. All rights reserved.

Joorabian M.,Shahid Chamran University | Afzalan E.,Shahid Chamran University
Applied Soft Computing Journal | Year: 2014

In this paper, we solve the optimal power flow problem using by the new hybrid fuzzy particle swarm optimisation and Nelder-Mead (NM) algorithm (HFPSO-NM). The goal of combining the NM simplex method and the particle swarm optimisation (PSO) method is to integrate their advantages and avoid their disadvantages. The NM simplex method is a very efficient local search procedure, but its convergence is extremely sensitive to the selected starting point. In addition, PSO belongs to the class of global search procedures, but it requires significant computational effort. In the other side, in the PSO algorithm, two variables (Φ1,Φ2) are traditionally constant; in this case, due to the importance of these two factors, we decided to obtain these two as fuzzy parameters. The proposed method is firstly examined on some benchmark mathematical functions. Then, it is tested an IEEE 30-bus standard test system by considering different objective functions for normal and contingency conditions to solve optimal power flow. The simulation results indicate that the FPSO-NM algorithm is effective in solving the mathematical functions and the OPF problem. © 2013 Elsevier B.V. All rights reserved.

Sedighi H.M.,Shahid Chamran University
International Journal of Applied Mechanics | Year: 2014

This paper is proposed to study the dynamic pull-in instability of nonlocal nanobridges incorporating the surface effect and intermolecular forces. The second-order frequency-amplitude relation is introduced via an asymptotic approach namely homotopy perturbation method (HPM). The effects of applied voltage and intermolecular parameters on pull-in instability as well as the natural frequency are investigated. Furthermore, the influence of nonlocal parameter and surface energy on the dynamic pull-in voltage is considered. It is shown that two terms in series expansions are sufficient to produce an acceptable solution of the mentioned nanostructure. The obtained results from numerical methods verify the strength of the analytical procedure. The qualitative analysis of the system dynamic shows that the equilibrium points of the autonomous system include center points with periodic trajectories and unstable saddle points with homoclinic orbits. © 2014 Imperial College Press.

This paper presents the impact of vibrational amplitude on the dynamic pull-in instability and fundamental frequency of actuated microbeams by introducing the second order frequency-amplitude relationship. The nonlinear governing equation of microbeam predeformed by an electric force including the fringing field effect, based on the strain gradient elasticity theory is considered. The predicted results of the strain gradient elasticity theory are compared with the outcomes that arise from the classical and modified couple stress theory. The influences of basic nondimensional parameters on the pull-in instability as well as the natural frequency are investigated by a powerful asymptotic approach namely the Parameter Expansion Method (PEM). It is demonstrated that two terms in series expansions are sufficient to produce an acceptable solution of the microstructure. The phase portrait of the microstructure shows that by increasing the actuation voltage parameter, the stable center point loses its stability and coalesces with unstable saddle node. © 2013 IAA.

Akbarizadeh G.,Shahid Chamran University
IEEE Transactions on Geoscience and Remote Sensing | Year: 2012

In this paper, an efficient algorithm for texture recognition of synthetic aperture radar (SAR) images is developed based on wavelet transform as a feature extraction tool and support vector machine (SVM) as a classifier. SAR image segmentation is an important step in texture recognition of SAR images. SAR images cannot be segmented successfully by using traditional methods because of the existence of speckle noise in SAR images. The algorithm, proposed in this paper, extracts the texture feature by using wavelet transform; then, it forms a feature vector composed of kurtosis value of wavelet energy feature of SAR image. In the next step, segmentation of different textures is applied by using feature vector and level set function. At last, an SVM classifier is designed and trained by using normalized feature vectors of each region texture. The testing sets of SAR images are segmented by this trained SVM. Experimental results on both agricultural and urban SAR images show that the proposed algorithm is effective for classification of different textures in SAR images, and it is also insensitive to the intensity. © 2012 IEEE.

Saki A.,Shahid Chamran University
Gondwana Research | Year: 2010

The Iran continental crust was metamorphosed, intruded by granitoid magmas, folded and faulted during the Late Precambrian by the Pan-African Orogeny. The basement complex in the Takab Complex (northwest Iran) consists of gneisses, amphibolites, pelitic schists, meta-ultramafic and calc-silicate rocks. Geochemically, the protoliths of the Takab gneisses are slightly peraluminous and medium to high-potassic with calc-alkaline affinity. These gneisses may have been emplaced in volcanic arc tectonic setting. Furthermore, the metapelitic protolith is shale deposited in an active continental margin setting. All these characteristics, and presence of paleo-suture zone and ophiolitic rocks (i.e. serpentines, meta-mafic and meta-ultramafic rocks) around the high grade metamorphic rocks suggest that a continental-margin magmatic arc (Andean-type) formed the Takab Precambrian basement. The basement complexes are extensively overprinted by the Pan-African Orogeny and younger igneous events; this supports the inference that Early Cambrian orogenesis in the Takab Complex region of northwest Iran marks one of the fundamental lithospheric boundaries within Gondwana which belonged to a greater Late Neoproterozoic-Early Paleozoic orogenic system that was active along the Proto-Tethyan margin of the Gondwana supercontinent, extending at least from its Arabian margin to the Himalayan margin of the Indian subcontinent. Crown Copyright © 2009.

The problem of finding analytical solutions for time-dependent or time-independent heat equations, especially for solid-state laser media, has required a lot of work in the field of thermal effects. However, to calculate the temperature distributions analytically, researchers often have to make some approximations or employ complex methods. In this work, we present full analytical solutions for anisotropic timedependent heat equations in the Cartesian coordinates with various source terms corresponding to various pumping schemes. Moreover, the most general boundary condition of Robin (or impedance boundary condition), corresponding to the convection cooling mechanism, was applied. This general condition can be easily switched to constant temperature and thermal insulation as special cases. To this end, we first proposed a general approach to solving time-dependent heat equations with an arbitrary heat source. We then applied our approach to explore the temperature distribution for three cases: steady-state pumping or long transient, single-shot pumping or short transient, and repetitively pulsed pumping. Our results show the possibility of an easier and more accurate approach to analytical calculations of the thermal dispersion, thermal stresses (strains), thermal bending, thermal phase shift, and other thermal effects. © 2012 Optical Society of America.

Regarding the green chemistry's goals, silica-coated magnetite nanoparticles (MNPs) open up new avenue to introduce an amazing and efficient system for facilitating catalyst recovery in different organic reactions. Therefore, in this paper the preparation of sulfuric acid functionalized silica-coated magnetite nanoparticles with core-shell structure (Fe 3O4@silica sulfuric acid) are presented by using Fe 3O4 spheres as the core and silica sulfuric acid nanoparticles as the shell. The catalyst was characterized by infrared spectroscopy (FT-IR), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) spectroscopy, and vibrating sample magnetometer (VSM). Ability of this nanomagnetic solid acid catalyst in the one-pot three-components condensation reaction of phthalhydrazide, aromatic aldehydes and cyclic or acyclic 1,3-diketones are also described. Utilization of easy reaction conditions, catalyst with high catalytic activity and good reusability, and simple magnetically work-up, makes this methodology as an interesting option for the economic synthesis of indazolo[2,1-b]phthalazine- triones and pyrazolo[1,2-b]phthalazine-diones. © 2013 Elsevier B.V.

Haghighi A.,Shahid Chamran University
Journal of Water Resources Planning and Management | Year: 2013

The design of urban drainage systems consists of solving two subproblems: (1) generating the layout and (2) sizing the sewers. The latter includes pipe diameters, installation depths, and pumping facilities, all of which are significantly influenced by the layout configuration. This work aims at introducing a method to solve the layout subproblem based on the graph theory. For a given city, all possible sewer lines and manholes are considered for the sewer network so that an undirected looped graph is initially formed. Next, an adaptive procedure entitled the loop-by-loop cutting algorithm is developed to create feasible sewer layouts from the base graph. Using this algorithm, all constraints of the sewer layout subproblem are systematically handled. By defining an objective function, the optimum layout is achieved by employing a simple genetic algorithm. After the sewer layout is determined, the specifications for pipes and pumps are designed by using a discrete differential dynamic programming model. A benchmark sewer system is also considered from the literature to be optimized. The results are discussed and compared with previous studies. It is concluded that the loop-by-loop cutting algorithm is especially useful for the design of urban drainage systems in flat areas. The method is also computationally efficient and easy to implement and add to optimization solvers. © 2013 American Society of Civil Engineers.

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