Tehran, Iran

Kharazmi University

Tehran, Iran

Kharazmi University is considered as the oldest institution of higher education in Iran named after Khwarizmi , Persian mathematician, astronomer and geographer. Kharazmi University is a major institution of higher education, offering a wide range of undergraduate and postgraduate programs in a variety of disciplines. It was established in 1919 as the Central Teachers' Institute and over a series of developments, finally gained university status as Tarbiat Moallem University of Tehran in 1974. It changed its name to Kharazmi University in 2010.Today the university is one of the largest in Iran with faculties of Science, Engineering, Mathematical & Computer science, Persian Literature and Humanities, Psychology & Education, Physical Education & Sport science and Chemistry. The university has two campuses,the main campus in the Hesarak area of Karaj and one in central Tehran . The current president of the university is Dr. Mohammad Ali Sobhanallahi. Wikipedia.

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The Noakoh anticline is located in Kermanshah province and is part of the Simply Folded Belt of Zagros. Boundaries of 97 triangular facets and 67 wine-glass (W-G) valleys, which formed on anticline limbs, were delineated using Quickbird satellite imagery. The strata dip (D), area (A), base length (BL), topographic slope (S) of facets, the maximum width (M), outlet width (O) and ratio of maximum width to outlet width (W index) of W-G valleys were analysed in detail. Noakoh anticline was subdivided into 9 tectonic zones on the basis of dip, topographic slopes and width of limbs. Results show that there are strong positive correlations between means of D-BL and S-BL pairs. Poor positive correlations exist between means of D-A and S-A pairs. Among W-G valley metrics, the W index has strong relations with D and S parameters. Based on the results, steep facets with long bases and well developed W-G valleys with narrow outlets and wide upper parts are associated with more rotated limbs having steep slopes. Facets on the northeastern slope have more forest cover, micro-organism activity, karstic features and soil cover, whereas facets on relatively drier southwestern slope are characterized by physical weathering processes and minor karstic landforms. This study demonstrates that, apart from tectonic activity as a major control on the morphometry of facets and valleys, climate and slope aspect have also acted as secondary factors on the development of the studied landforms. © 2012 Elsevier B.V.

Hamidi A.,Kharazmi University | Hooresfand M.,Kharazmi University
Geotextiles and Geomembranes | Year: 2013

Conventional triaxial compression tests were conducted to determine the effect of cement and polypropylene fiber reinforcement on sand. The cement content was 3% (dry wt.) of the sand and specimens were cured for seven days. Fibers 0.012 m in length and 23 μm thick were added at 0.0%, 0.5% and 1% (dry wt.) of the sand-cement mixture. Samples were prepared at 50% and 70% relative densities and triaxial tests were performed at confining pressures of 100, 300 and 500 kPa. Stress-strain and volume change behavior, and stiffness and energy absorption of the soil were measured and compared with results of previous studies. The addition of fibers increased peak and residual shear strengths of cemented soil and changed its brittle behavior to a more ductile one. Initial stiffness for 0.1% axial strain decreased as fiber content increased. Adding fiber increased the energy absorption by 20-50%. Fibers were more effective on shear strength parameters at 70% relative density. © 2012 Elsevier Ltd.

A new carbon paste electrode chemically modified with TiO2 nanoparticles (TiO2NP-MCPE) is constructed and used for the selective and sensitive electrochemical determination of trace amounts of clozapine (CLZ). The effect of carbon paste composition, working solution pH and scan rate were studied with this modified electrode. The presence of TiO2 nanoparticles in the carbon paste increased the available surface area of the electrode and improved the sensitivity by enhancing peak currents. The electrochemical behavior of the modified electrode and the mechanism of the oxidation of CLZ were investigated using cyclic voltammetry (CV). From the slope of the Tafel plot the α value was found 0.57. Using adsorptive differential pulse voltammetry (AD-DPV) at optimum parameters a linear dynamic range of 0.5-45 μM clozapine was observed with detection limit of 61.0 nM. In addition, the CLZ and thioridazine were determined simultaneously using TiO2NP-MCPE in AD-DPV. In AD-DPV measurements, used TiO 2NP-MCPE, the oxidation peak potentials of CLZ and thioridazine was separated about 260 mV. The voltammograms showed two anodic peaks at 370 and 630 mV vs. Ag/AgCl, corresponding to the oxidation of CLZ and thioridazine, respectively. Finally, this method was used for determination of CLZ in clozapine tablets with satisfactory results. © 2012 Elsevier Ltd.

Molecular dynamics simulation has been performed to obtain pressure, radial distribution function, and self-diffusion coefficient of fluid methane using one site OPLS (optimized potentials for liquid simulations), five sites OPLS-SITE, and two-body HFD (Hartree-Fock dispersion)-like potentials. To take higher-body forces into account, three-body potential of Hauschild and Prausnitz (1993) has been used with the two-body HFD-like potential. The significance of this work is that the three-body potential of Hauschild and Prausnitz extended as a function of density and temperature and used with the HFD-like potential to improve the prediction of the results of pressure of fluid methane without requiring an expensive three-body calculation. The molecular dynamics simulation of methane has been also used to determine a new equation of state. The results are in a good agreement with experimental and theoretical values. © 2011 Elsevier B.V.

Fathabadi H.,Kharazmi University
Energy Conversion and Management | Year: 2013

In this paper, a novel method is proposed to determine the characteristics of silicon solar cell, module and plastic solar cell. Feed-forward artificial neural network together with Lambert W function are used to determine the characteristics. The current-voltage (I-V) and power-voltage (P-V) curves of silicon/plastic solar cells and module are determined. Five model parameters of the solar cell and module are calculated using the proposed technique which compares the Lambert W function representation of the current-voltage characteristic with the learned feed-forward neural network model of the current-voltage relation. Simulation results show a very good agreement between the calculated characteristic curves and experimental data. Also errors are calculated to evaluate the accuracy of the proposed method. The accuracy of the proposed method is compared with other related methods to validate the superiority of the proposed method. As will be shown, the novel contributions of the proposed method can be summarized as: firstly, the proposed method has the accuracy which is much better than other methods and secondly, the current and power errors in the proposed method are generally very lower than these errors in other methods even at the Maximum Power Point (MPP). © 2013 Elsevier Ltd. All rights reserved.

Farash M.S.,Kharazmi University
Peer-to-Peer Networking and Applications | Year: 2016

Very recently, Tu et al. proposed an authentication scheme for session initiation protocol using smart card to overcome the security flaws of Zhang et al.’s protocol. They claimed that their protocol is secure against known security attacks. However, in this paper, we indicate that Tu et al.’s protocol is insecure against impersonation attack. We show that an adversary can easily masquerade as a legal server to fool users. As a remedy, we also improve Tu et al.’s protocol without imposing extra computation cost. To show the security of our protocol, we prove its security in the random oracle model. © 2014, Springer Science+Business Media New York.

In this study, a novel Li-ion battery pack design including hybrid active-passive thermal management system is presented. The battery pack is suitable for using in hybrid/electric vehicles. Active part of the hybrid thermal management system uses distributed thin ducts, air flow and natural convection as cooling media while the passive part utilizes phase change material/expanded graphite composite (PCM/EG) as cooling/heating component to optimize the thermal performance of the proposed battery pack. High melting enthalpy of PCM/EG composite together with melting of PCM/EG composite at the temperature of 58.9°C remains the temperature distribution of the battery units in the desired temperature range (below 60°C). The temperature and voltage distributions in the proposed battery pack design consisting of battery units, distributed thin ducts and PCM/EG composite are calculated by numerical solving of the related partial differential equations. Simulation results obtained by writing M-files code in Matlab environment and plotting the numerical data are presented to validate the theoretical results. A comparison between the thermal and physical characteristics of the proposed battery pack and other latest works is presented that explicitly proves the battery pack performance. © 2014 Elsevier Ltd.

Fathabadi H.,Kharazmi University
Journal of Power Sources | Year: 2014

In this paper, a novel design including cooling media for packing the rechargeable Lithium (Li)-ion batteries used in hybrid and electric vehicles is proposed. The proposed battery pack satisfies all thermal and physical issues relating to the battery packs used in vehicles such as operating temperature range and volume, and furthermore it increases the battery life cycle and charge and discharge performances. The temperature and voltage distributions of the proposed battery pack are calculated using the characteristics of a sample Li-ion battery and heat transfer principles. The proposed battery pack uses several distributed thin ducts for cooling which is based on distributed natural convection. Ultra uniform voltage and temperature distributions, minimum temperature dispersion in each battery unit, minimum increase in the battery pack volume, natural convection (no extra energy consumption for cooling), the maximum observed temperature less than that in other proposed battery packs and high thermal performance for different ambient temperatures until 48°C are some advantages of the proposed Li-ion battery pack including proposed distributed cooling media. Simulation results and a comparison between the parameters of the proposed cooling media and other related work are presented to validate the theoretical results and to prove the superiority of the proposed battery pack design. © 2013 Elsevier B.V. All rights reserved.

Mohammadikish M.,Kharazmi University
Ceramics International | Year: 2014

A facile hydrothermal method for the synthesis of α-Fe 2O3 nanocrystals is described. The crystalline structure and morphology of the as-prepared product were investigated by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Powder X-ray diffraction pattern exhibited pure rhombohedral structure. The SEM and TEM results showed that the average diameter of the highly crystalline ellipsoid shape α-Fe2O3 nanocrystals was about 40-50 nm. The band gap energies were investigated by the UV-vis absorption studies. © 2013 Elsevier Ltd and Techna Group S.r.l.

Khakpai F.,Kharazmi University
Behavioural Brain Research | Year: 2014

Background and aim: Removal of the testes (gonadectomy; GDX), the primary source of androgens, increases anxiety behavior in several tasks. Opioids are known to play a role in mediating the effects of androgen. In the present study, the effect of testosterone and opioidergic system on anxiety behavior was investigated. Methods: Adult male Wistar rats were bilaterally castrated. The elevated plus maze which is a useful test to investigate the effects of anxiogenic or anxiolytic drugs in rodents was used. Results: The data indicated that there is a decrease, 10 days after castration, in the percentage of OAT (the ratio of time spent in the open arms to total times spent in any arms. ×. 100) and OAE (the ratio of entries into open arms to total entries. ×. 100) but not locomotor activity, showing anxiogenic-like effects of gonadectomy. Intraperitoneal injection of testosterone (200, 300 and 450. mg/kg) and morphine (2.5, 5 and 7.5. mg/kg), before testing 10 days after castration, showed an increase in OAT and OAE. Furthermore, injection of naloxone (5 and 7.5. mg/kg, i.p.), 5. min before testing 10 days after castration, decreased OAT and OAE. Also, injection of a significant dose of testosterone (300. mg/kg, i.p.), 1. h before the injection of different doses of morphine (1, 2.5, 5 and 7.5. mg/kg, i.p.), 10 days after castration, did not significantly alter OAT, OAE and locomotor activity. While, administration of a significant dose of testosterone (300. mg/kg, i.p.), 1. h before the infusion of different doses of naloxone (1, 2.5, 5 and 7.5. mg/kg, i.p.), 10 days after castration, decreased OAT and OAE. Conclusion: The results show the involvement of testosterone and opioidergic system in anxiogenic-like behaviors induced by gonadectomy. © 2014 Elsevier B.V.

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