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Hekmati P.,Illinois Institute of Technology | Yazdanpanah R.,Islamic Azad University at Larestan | Mirsalim M.,Amirkabir University of Technology | Ghaemi E.,Amirkabir University of Technology
IEEE Transactions on Industrial Electronics | Year: 2017

Slotless radial-flux permanent-magnet limited-angle torque motor with disturbed armature winding is analyzed in this paper. For the first time, the outer rotor structure is investigated for this type of the rotary actuator. The exact 2-D analytical modeling is applied to obtain the magnetic field parameters of the windings and excitation for both the outer rotor and the conventional inner rotor topologies. Also, the governing and geometrical equations are derived based on the analysis outcomes. Then, they are validated by applying the finite-elements tool. Both topologies are designed and compared with each other considering a variety of utilization parameters of these actuators. Avoiding saturation is considered as a designing criterion, which corresponds to the maximum torque production without distortion of linear characteristics in short-time operations. Experimental results show good accuracy of the theoretical design and numerical simulations. Comparison of the results shows significantly better performance of the new proposed actuator with the outer rotor structure against the conventional inner rotor type. © 2016 IEEE.


Rokhgireh H.,Islamic Azad University at Larestan | Nayebi A.,Shiraz University | Chaboche J.L.,ONERA
International Journal of Solids and Structures | Year: 2017

This paper is concerned with the ratcheting prediction for steels. The yield surface evolution is integrated in the elastoplasticity analysis by a new proposed model. First, the new proposed model of Distortional Yield Surface (DYS) is developed and then ratcheting under different uniaxial and multiaxial cyclic loadings is investigated. The capabilities of the DYS model is assessed by using the results of various stress-controlled and strain-controlled tests under uniaxial loading condition and the cyclic uniaxial experimental results of Hassan and Kyriakides (1994a). In addition, the model prediction under multi-steps uniaxial loadings is also studied. Effects of DYS consideration in different uniaxial loadings are shown. Strain or stress controlled tests and combined stress-strain control experimental tests (Hassan and Kyriakides, 1994b) are used to be modeled by the present distortional yield surface approach. The biaxial experiments on CS 1018 thin-walled tubes (Hassan and Kyriakides, 1994b) are chosen to be compared with the present model results. With the incorporation of DYS, The new proposed model shows better prediction of uniaxial and multiaxial ratchetting in all ranges of experimentally tested parameters. © 2017.


Rokhgireh H.,Islamic Azad University at Larestan | Nayebi A.,Shiraz University
Mechanics Research Communications | Year: 2016

In this study, a yield surface distortion model coupled with nonlinear kinematic hardening model is proposed. The new yield surface distortion model is used to simulate proportional and non-proportional cyclic loading paths. Distortion of the yield surface and its nonlinear effects on the plastic flow have been studied by researchers and various models. However, these models have been rarely applied to different non-proportional cyclic loading paths. The yield surface evolution is obtained by the new model in cyclic loading and its results are compared with the experimental results of Dannemeyer [30]. The new model with few constants predicts well the yield surface evolution under non-proportional loading paths which leads to well comparison of the numerical results with respect to the experimental results. © 2016 Elsevier Ltd. All rights reserved.


Norouzi M.,Islamic Azad University at Larestan | Mansouri B.,Islamic Azad University at Kermānshāh | Hamidian A.H.,University of Tehran | Zarei I.,Islamic Azad University at Larestan | Mansouri A.,University of Kurdistan
Bulletin of Environmental Contamination and Toxicology | Year: 2012

The purpose of this study was to determine the concentrations of metals, cadmium, chromium, lead and nickel in Liza vaigiensis and Johnius carutta, in order to: compare metal concentrations between two species with different gender, and to determine the significance between metal concentrations in the gill, liver and muscle. The highest mean concentrations of cadmium, chromium, lead and nickel in different tissues of these two fish species were found in the liver of L. vaigiensis at 0.68, 0.83, 0.37 and 1.42 μg g-1, respectively; while the lowest mean concentrations of cadmium, chromium, lead and nickel were observed in the muscle of J. carutta at 0.16, 0.16, 0.03 and 0.29 μg g-1, respectively. The results showed that the metal concentrations in both species were higher in the females than in the males (except chromium in gill and cadmium in muscle of J. carutta). Also, the results indicated that the metal concentrations were different among fish tissues (one-way ANOVA, p < 0.001), but there was no difference (except lead in gills of J. carutta) between sex (male vs. female). © Springer Science+Business Media, LLC 2012.


Fanaei H.,Shiraz University of Medical Sciences | Keshtgar S.,Shiraz University of Medical Sciences | Bahmanpour S.,Shiraz University of Medical Sciences | Ghannadi A.,Islamic Azad University at Larestan | Kazeroni M.,Shiraz Fertility and Infertility Center
Reproductive Sciences | Year: 2011

Calcium (Ca 2+) and reactive oxygen species (ROS) constitute the most influential intracellular signaling molecules participating in the regulation of different sperm functions. Elevating intracellular Ca 2+ and ROS in physiologic range regulate capacitation, motility, acrosome reaction, and sperm-oocyte fusion; whereas cytosolic Ca 2+ overload and ROS overproduction have pathologic effects. Our aim of this study was determination of antioxidant effects of α-tocopherol on sperm motility, viability, and DNA integrity in a condition where cytosolic calcium overload was induced by A23187 (a calcium ionophore). Our results indicated that, α-tocopherol has ability to prevent sperm mortality and save sperm rapid motility after 1 hour incubation. At the same time, A23187 reduced significantly percentage of rapid sperm motility and increased sperm mortality and DNA damage. Results of sperms incubation in the medium contain a combination of A23187 and α-tocopherol showed that α-tocopherol can reduce many of the deleterious effects of A23187. In conclusion, it seems that the harmful effects of A23187 are due to excessive ROS production, and α-tocopherol neutralizes these effects. © Society for Gynecologic Investigation 2011.


Pahlavanpoorfard S.,Islamic Azad University at Larestan | Soori A.,Islamic Azad University at Larestan
International Journal of Applied Linguistics and English Literature | Year: 2014

Today, using computer is common in all fields. Education is not an exception. In fact, this approach of technology has been using increasingly in language classrooms. We have witnessed there are more and more language teachers are using computers in their classrooms. This research study investigates the impact of using computer on vocabulary learning of Iranian EFL university students. To this end, a sample of 40 university students in Islamic Azad University, Larestan branch were randomly assigned into the experimental and control groups. Prior the treatment and to catch the initial deferences between the participants, all the students sat for a pre-test that was an Oxford Placement Test. Then the students were received the treatment for 10 weeks. The students in the experimental group were taught by computer software for vocabulary learning while the students in the control group were taught through traditional method for vocabulary learning. After the treatment, all the students sat for a post-test. The statistical analysis through running Independent-Sample T-tests revealed thatthe students in the experimental group who used the computer software for vocabulary learning performed better than the students in the control group were taught through traditional method for vocabulary learning. © Australian International Academic Centre, Australia.


Esmaeeli H.,Islamic Azad University at Larestan | Soori A.,Islamic Azad University at Larestan
International Journal of Applied Linguistics and English Literature | Year: 2014

This study set out to investigate whether the knowledge of semantic macro-structures on the report writing of Iranian EFL students in terms of three main categories of rating, namely structure, vocabulary, and organization. This study is a true experimental design which provides pretest of general proficiency test as well as pretest of writing ability. It also involves treatment program for the experimental group and placebo for the control group and finally a posttest of writing. The participants of this study were 40 male upper-intermediate Iranian EFL students studying English in two well-known English institutes of Jahrom. Having used t-test, the researcher found that there was no significant difference between the subjects’ reports vocabulary, structure, and organization quality across groups of control and experimental. © Australian International Academic Centre, Australia.


Akbari S.,Islamic Azad University at Larestan
10th International Conference on e-Commerce in Developing Countries: With Focus on e-Tourism, ECDC 2016 | Year: 2016

E-Commerce technologies have changed the economy bases of some business in the recent years. This paper represents in more details the industrial complexities which have changed the industrial economic structures around the world. Initially, we bring two factors that have been considered occasionally with the information technologies, such as, the changing balance of power in the specific industries and more efficient coordination of activities within and between enterprises. Then, we investigate three other factors brought by internet with high priority and effects on the value chains of industries. Simply stated these three factors are: disintermediation, disaggregation, and digital convergence. Although effects of these factors have been previously observed and studied, they have gained more significance in today technological era as the results of World Wide Web special benefits in the recent years. © 2016 IEEE.


Moosavi S.M.R.,Islamic Azad University at Larestan | Sadeghi-Niaraki A.,K. N. Toosi University of Technology
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2015

Nowadays more advanced sensor networks in various fields are developed. There are lots of online sensors spreading around the world. Sensor networks have been used in Geospatial Information Systems (GIS) since sensor networks have expanded. Health monitoring, environmental monitoring, traffic monitoring, etc, are the examples of its applications in Geomatics. Sensor network is an infrastructure comprised of sensing (measuring), computing, and communication elements that gives an administrator the ability to instrument, observe, and react to events and phenomena in a specified environment. This paper describes about development boards which can be used in sensor networks and their applications in Geomatics and their role in wireless sensor networks and also a comparison between various types of boards. Boards that are discussed in this paper are Arduino, Raspberry Pi, Beagle board, Cubieboard. The Boards because of their great potential are also known as single board computers. This paper is organized in four phases: First, Reviewing on ubiquitous computing and sensor networks. Second, introducing of some electrical boards. Then, defining some criterions for comparison. Finally, comparing the Ubiquitous boards.


Karkon M.,Islamic Azad University at Larestan | Rezaiee-Pajand M.,Ferdowsi University of Mashhad
Journal of Engineering Mechanics | Year: 2016

This study deals with the geometric nonlinear analysis of the plane problem based on the corotational formulation. Both analytical solutions and hybrid stress functional will be utilized in the proposed technique. A quadrilateral four-node element with drilling degrees of freedom is proposed for the finite-element analysis. The corotational method is applied for the nonlinear behavior. In this way, small strains and rigid body motions can be separated. Based on analytical solution, the hybrid stress scheme is used in the local coordinates for small strains. By using Allman's quadratic displacement, the boundary condition for this element is introduced. In this approach, added drilling degrees of freedom increase the accuracy and robustness of the element. Furthermore, the corotational formulas are written in the local and global coordinates system to derive the nonlinear relations. These equations were solved by using the arc-length algorithm. To investigate the accuracy and capability of the suggested element, several numerical tests are performed. Findings prove the advantage of the proposed element in the geometric nonlinear analysis of plane problems. © 2016 American Society of Civil Engineers.

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