Azarbaijan Shahid Madani University, , , commonly called only Azarbaijan University, is a public university located near Tabriz, East Azarbaijan Province, Iran, founded in 1987. The university provides bachelor, master, and doctoral education to about 7.500 students at a wide range of fields of study such as engineering, basic scienses, literature and theology. Wikipedia.
Habibi B.,Shahid Madani University of Azarbaijan
International Journal of Hydrogen Energy | Year: 2013
Palladium nanoparticles were fabricated on the aluminum electrode (Pd/Al) by electrodeposition method through a single step potential from an aqueous solution of 1 mM Pd(NH3)4Cl2. The electrochemical and physical characteristics of the Pd/Al were investigated by cyclic voltammetry, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) method. Electrochemical measurements in acidic solution indicate that Pd/Al exhibits significantly high electrochemical active surface area (18.32 cm2) with respect to Pd-Al (2.1 cm2) (electroless deposited) and bare Pd (0.28 cm2) electrodes. SEM images and XRD results show that the Pd particles are homogeneously deposited on the surface Al substrate in nanoparticles size between 30 and 50 nm with maximum Pd (111) plane at 2θ angles about of 39°. The Pd/Al was used as electrocatalyst for the oxidation of formic acid (FA) in 0.1 M H2SO4 solution. The cyclic voltammetry and chronoamperometry results show that the obtained electrocatalyst, Pd/Al, exhibits high catalytic activity and stability for the electrooxidation of FA. On the other hand, the Pd/Al electrocatalyst has higher catalytic activity for FA oxidation than the comparative Pd-Al and bare Pd electrodes and shows great potential as less expensive electrocatalyst for FA oxidation in direct formic acid fuel cells. Crown Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Mokhberdoran A.,University of Porto |
Ajami A.,Shahid Madani University of Azarbaijan
IEEE Transactions on Power Electronics | Year: 2014
Nowadays, use of multilevel inverters in high-power applications clearly can be seen. High quality and lower distortion of the output voltage and low blocking voltage of semiconductor switches are being presented as the major privileges of the multilevel inverter compared to the traditional voltage source inverter. In this paper, a new topology of multilevel inverter is proposed as fundamental block. The proposed topology is generalized using series connection of the fundamental blocks. The proposed multilevel inverter has been analyzed in both symmetric and asymmetric operation modes. A great perfection in voltage levels number with minimum switching devices has been obtained in both symmetric and asymmetric modes. Thereafter, a detailed study of losses and peak inverse voltage (PIV) of the proposed multilevel inverter is given. Also, in continuation, a comparison between the proposed topology and the traditional one and a recently developed topology is carried out. Finally, a computer simulation using MATLAB/Simulink is presented and a laboratory prototype implementation verifies the results. © 2014 IEEE.
Atazadeh K.,Shahid Madani University of Azarbaijan |
Darabi F.,Shahid Madani University of Azarbaijan
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015
We study the stability of Einstein static Universe, with FLRW metric, by considering linear homogeneous perturbations in the kinetic coupled gravity. By taking linear homogeneous perturbations, we find that the stability of Einstein static Universe, in the kinetic coupled gravity with quadratic scalar field potential, for closed (K=1) isotropic and homogeneous FLRW Universe depends on the coupling parameters κ and ε. Specifically, for κ=LP2 and ε=1 we find that the stability condition imposes the inequality a0>3LP on the initial size a0 of the closed Einstein static Universe before the inflation. Such inequality asserts that the initial size of the Einstein static Universe must be greater than the Planck length LP, in consistency with the quantum gravity and quantum cosmology requirements. In this way, we have determined the non-minimal coupling parameter κ in the context of Einstein static Universe. Such a very small parameter is favored in the inflationary models constructed in the kinetic coupled gravity. We have also studied the stability against the vector and tensor perturbations and discussed on the acceptable values of the equation of state parameter. © 2015 The Authors.
Shaghaghi Z.,Shahid Madani University of Azarbaijan
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014
Due to their potential applicability as selective receptors in optical sensors, two novel azo Schiff-base derivatives I and II are synthesized and characterized with FT-IR, 1H NMR and elemental analysis techniques. The optical response of azo groups of I and II towards Ni2+, Co 2+, Cu2+, Pb2+, Hg2+, Zn 2+ and Cd2+ metal ions is studied in DMSO by UV-vis spectroscopy. The absorption spectra of both compounds with cations show marked changes. In solution, azo Schiff-base I produces a cation induced 95 nm blue shift for Cu2+ ion from 555 nm to 460 nm with remarkable color change from red to yellow. Whereas no significant color change is observed upon addition of studied metal cations to the solution of ligand II or other metal ions to the solution of ligand I. Furthermore, Job's plot indicate 1:1 binding-stoichiometry for I with Cu2+ ion and Benesi-Hildebrand plot is used for the determination of its association constant. Therefore receptor I is highly specific for copper ions in DMSO solution. Finally, the study of antioxidant properties of I and II with DPPH method reveals high and significant activities. © 2014 Elsevier B.V. All rights reserved.
Razmi H.,Shahid Madani University of Azarbaijan |
Mohammad-Rezaei R.,Shahid Madani University of Azarbaijan
Biosensors and Bioelectronics | Year: 2013
Graphene quantum dots (GQD) were introduced as a novel and suitable substrate for enzyme immobilization. Glucose oxidase (GOx) was immobilized on GQD modified carbon ceramic electrode (CCE) and well-defined quasi-reversible redox peaks were observed. The UV-vis photoluminescence spectroscopy, transition electron microscopy, field emission scanning electron microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry techniques were used for characterizing the electrochemical biosensor. The electron transfer coefficient (α) and the heterogeneous electron transfer rate constant (ks) for redox reaction of GOx were found to be 0.48 and 1.12s-1, respectively. The developed biosensor responds efficiently to glucose presence over the concentration range 5-1270μM with the detection limit 1.73μM (S/N=3) and sensitivity 0.085μAμM-1cm-2. The high value of surface coverage GOx-GQD|CCE (1.8×10-9mol/cm2) and the small value of Michaelis-Menten constant (0.76mM) confirmed an excellent loading of the enzyme and a high affinity of biosensor to glucose. High performance of the biosensor is attributed to the large surface-to-volume ratio, excellent biocompatibility of GQD, porosity of GQD|CCE, and the abundance of hydrophilic edges as well as hydrophobic plane in GQD which enhances the enzyme absorption on the electrode surface. © 2012 Elsevier B.V.
Atazadeh K.,Shahid Madani University of Azarbaijan
Journal of Cosmology and Astroparticle Physics | Year: 2014
The existence and stability of the Einstein static solution have been built in the Einstein-Cartan gravity. We show that this solution in the presence of perfect fluid with spin density satisfying the Weyssenhoff restriction is cyclically stable around a center equilibrium point. Thus, study of this solution is interesting because it supports non-singular emergent cosmological models in which the early universe oscillates indeterminately about an initial Einstein static solution and is thus past eternal. © 2014 IOP Publishing Ltd and Sissa Medialab srl.
Aalipour R.,Shahid Madani University of Azarbaijan
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014
Spectral singularities are spectral points of non-Hermitian Hamiltonians with the real energies, that annihilate the completeness of the eigenfunctions. The complex PT-symmetric potentials with real spectrum have such Hamiltonians. It was identified that the spectral singularities of complex potentials such as an optical gain medium correspond to zero-width resonance modes of the reflected and transmitted beams from the medium. We show that a Fabry-Perot resonator with a gain medium under inclined incident beam exhibits spectral singularities that are measurable by changing the incident angle of the beam to the resonator. The results are realized by theory and simulations. © 2014 American Physical Society.
Darabi F.,Shahid Madani University of Azarbaijan
European Physical Journal C | Year: 2013
The breakdown of conformal symmetry in a conformally invariant scalar-tensor gravitational model is revisited in the cosmological context. Although the old scenario of conformal symmetry breaking in cosmology containing a scalar field has already been used in many earlier works, it seems that no special attention has been paid for the investigation on the possible connection between the breakdown of conformal symmetry and the existence of dark energy. In this paper, it is shown that the old scenario of conformal symmetry breaking in cosmology, if properly interpreted, not only has a potential ability to describe the origin of dark energy as a symmetry breaking effect, but also may resolve the coincidence problem. © 2013 Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica.
Mojaveri B.,Shahid Madani University of Azarbaijan
European Physical Journal D | Year: 2013
Based on the quantum states of an electron trapped on an infinite band along the x-axis in the presence of the Morse-like perpendicular magnetic field [H. Fakhri, B. Mojaveri, M.A. Gomshi Nobary, Rep. Math. Phys. 66, 299 (2010)], the Klauder-Perelomov and Gazeau-Klauder coherent states are constructed. To realize the resolution of identity, their corresponding positive definite measure on the complex plane are obtained in terms of the known functions. Also, some nonclassical properties such as sub-Poissonian statistics and squeezing effect of constructed coherent states are studied. © 2013 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.
Akbari-Moghanjoughi M.,Shahid Madani University of Azarbaijan
Journal of Plasma Physics | Year: 2013
By investigating the dielectric response of the Fermi-Dirac plasma in the linear limit and evaluating the electrostatic potential around the positive stationary test charge, we find that the Shukla-Eliasson attractive force is present for the plasma density range expected in the interiors of large planets for a wide range of plasma atomic number. This research, which is based on the generalized electron Fermi-momentum, further confirms the existence of the newly discovered Lennard-Jones-like attractive potential and its inevitable role in plasma crystallization in the cores of planets. Moreover, it is observed that the characteristics of the attractive potential are strongly sensitive to the variation of plasma density and composition. Current research can also have applications in the study of strong laser-matter interactions and inertially confined plasmas. © Cambridge University Press 2012.