Azadi M.,Islamic Azad University at Marvdasht |
Khosravi G.,Islamic Azad University at Arsanjan
ACM International Conference Proceeding Series | Year: 2017
In this paper, vibrations of a nonlinear composite beam is analyzed and an active controller is used to suppress the vibrations of the system. The beam is resting on a Winkler-Pasternak elastic foundation. The composite beam is reinforced by single walled carbon nanotubes. Using the rule of mixture, the material properties of functionally graded carbon nanotube-reinforced composites (FG-CNTRCs) are determined. The beam is cantilever and the free end of the beam is under follower force. Piezoelectric layers are attached to the both sides of the beam to control vibrations as sensors and actuators. The governing equations of the FG-CNTRC beam is derived based on Euler-Bernoulli beam theory. The simulation results are presented and the effects of some parameters on stability of the beam are analyzed. The simulation results show the high performance of the controller scheme. © 2017 Association for Computing Machinery.
Azadi M.,Islamic Azad University at Marvdasht |
Hasanshahi B.,Islamic Azad University at Arsanjan
Lecture Notes in Mechanical Engineering | Year: 2017
This research deals with a study of tracking and vibration control of a functionally graded carbon nanotube reinforced composite robotic arm which crosses pre-specified path. The Euler-Bernoulli beam theory and Lagrange-Rayleigh-Ritz technique are employed to derive the governing equations of CNTRC robotic arm. The robotic arm is subjected to a follower force; also, in order to control the vibration, the piezoelectric layers have been used beside the active control system. The robotic arm is simulated and the results show the effectiveness of the controller algorithm. © Springer International Publishing Switzerland 2017.
Zare A.,Islamic Azad University at Arsanjan |
Ghasemi M.,Moshiran consulting company
International Review on Modelling and Simulations | Year: 2010
Loads, generators, and power system's structures are effective factors that significantly affect the voltage stability. The selection of a sufficient model for loads has a significant effect on the accuracy of voltage stability analysis. The constant power load model is commonly used in voltage stability studies and specially in examining the effects of FACTS devices. However, the actual loads in power systems are not constant power. This paper focuses on the hidden effects of the interaction between loads and STATCOM on the voltage stability. Simulations results revealed the salient effect of loads on the STATCOM performance. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved.
Moayedi H.,University Putra Malaysia |
Asadi A.,Islamic Azad University |
Moayedi F.,Islamic Azad University at Arsanjan |
Huat B.B.K.,University Putra Malaysia
International Journal of Electrochemical Science | Year: 2011
The focus of this research is to study the influence of polyvinyl alcohol (PVA) adsorption on the zeta potential properties of two tropical soil namely peat, and kaolinite. Two different PVA species were used, partially hydrolyzed (PVA-T) as well as fully hydrolyzed (PVA-F). As results, adding the PVA species into the suspended colloids led to an increase of zeta potential in their surfaces, contrary to measuring done in water. The zeta potential of the Peat soil varied from 25.26 to -95.1 mV, according to the PVA type and concentration. Kaolinite, however, showed zeta potential varied from +32.4 to -161.78. Negative charge in both peat and kaolinite soils were highly pH dependent and their surface charge dropped to zero at pH 3.1 to 3.4. Using PVA cause a significant reduction in isoelectric point (IEP) of soil samples to about 1.9 for peat and 2.1 for kaolinite. PVA-F enhanced the negative zeta potential than PVA-T. However, increasing of zeta potential in negative sign with increasing degree of polymerization can be observed in both PVA-T and PVA-F samples. © 2011 by ESG.
Nasiri M.,Islamic Azad University at Arsanjan |
Rasti Z.,Islamic Azad University at Arsanjan
Human Immunology | Year: 2016
The purpose of the present study was to evaluate the possible association between CTLA-4 +49A/G and IL-6 -634C/G polymorphisms, and the risk of recurrent pregnancy loss (RPL). 240 women (120 healthy controls and 120 with RPL) were enrolled in this case-control study. Genotyping was performed using a PCR-RFLP technique. In the case of polymorphic CTLA-4 +49A/G, the wild type allele G was associated with a decreased risk of RPL (OR: 0.42, 95%CI: 0.25-0.69, p = 0.001). As to IL-6 -634C/G polymorphism, a highly significant difference was observed, and those women who carry at least one mutant G allele presented a probability of developing RPL about 5 times greater than controls (OR: 5.1, 95%CI: 1.04-25.3, p = 0.04). The results indicate that polymorphisms of CTLA-4 and IL-6 genes may influence the risk of developing RPL among Iranian women, suggesting that more research on the immunogenetics of pregnancy should be conducted to confirm our results, and to declare the exact roles of studied molecules in RPL pathogenesis. © 2016 American Society for Histocompatibility and Immunogenetics.
Nemati S.,Islamic Azad University at Arsanjan |
Basiri M.E.,University of Isfahan
Expert Systems with Applications | Year: 2011
With the growing trend toward remote security verification procedures for telephone banking, biometric security measures and similar applications, automatic speaker verification (ASV) has received a lot of attention in recent years. The complexity of ASV system and its verification time depends on the number of feature vectors, their dimensionality, the complexity of the speaker models and the number of speakers. In this paper, we concentrate on optimizing dimensionality of feature space by selecting relevant features. At present there are several methods for feature selection in ASV systems. To improve performance of ASV system we present another method that is based on ant colony optimization (ACO) algorithm. After feature reduction phase, feature vectors are applied to a Gaussian mixture model universal background model (GMM-UBM) which is a text-independent speaker verification model. The performance of proposed algorithm is compared to the performance of genetic algorithm on the task of feature selection in TIMIT corpora. The results of experiments indicate that with the optimized feature set, the performance of the ASV system is improved. Moreover, the speed of verification is significantly increased since by use of ACO, number of features is reduced over 80% which consequently decrease the complexity of our ASV system. © 2010 Elsevier Ltd. All rights reserved.
Zarei M.,Hormozgan University |
Mohamadzadeh M.,Islamic Azad University at Arsanjan
Tetrahedron | Year: 2011
A series of 3-thiolated β-lactams were synthesized by [2+2] ketene-imine cycloaddition reaction from S-substituted mercaptoacetic acids and Schiff bases. Then, some of the 3-methylthio β-lactams were converted to 3-(methylsulfinyl) β-lactams and 3-(methylsulfonyl) β-lactams using m-CPBA under different reaction conditions. All the compounds were characterized by spectral data and elemental analyses and were evaluated for their in vitro antibacterial and antifungal activities against pathogenic strains including Staphylococcus aureus (Methicillin resistant strain). The preliminary screening results indicated that some of these compounds demonstrated moderate to very good antibacterial and antifungal activities. © 2011 Elsevier Ltd. All rights reserved.
Mashizi M.K.,Islamic Azad University at Arsanjan |
Rezaian F.,Islamic Azad University at Arsanjan
Advances in Environmental Biology | Year: 2014
The purpose of this study was to investigate the effects of computer-assisted instruction on learning natural sciences by 2nd grade elementary students in Bardsir (a city in Kerman Province) in 2012-2013 academic years. To investigate the problem, a quasiexperimental design with two experimental and control group was employed. The sample under study was 54 second grade elementary students (28 students in the experimental group and 26 students in the control group). The participants were selected via multi-stage cluster random sampling method. The instrument used to collect the data was a researcher made test on learning sciences based on Bloom's cognitive levels. The results of analysis of covariance suggested that computer-assisted instruction has a significant effect on learning natural sciences by the second grade elementary students. It was also noted that computer-assisted instruction affects the recall of materials learned in the natural sciences course by the second elementary students. Computer-assisted instruction also affects the comprehension of materials learned in the natural sciences course by the second grade elementary students. Furthermore such instruction can affect the application and the use of materials presented in the natural sciences course by the second grade elementary students. Finally, it was observed that computer-assisted instruction has an effect on the analysis and synthesis of materials presented in the natural sciences course by the second grade elementary students. © 2014 AENSI Publisher All rights reserved.
Miri H.R.,Islamic Azad University at Arsanjan
Advances in Environmental Biology | Year: 2011
Allelopathy, the ability of plants to inhibit growth of other plants, is a potential source for weed control in crops that can use in sustainable crop production. In order to evaluate allelopathic potential of some important crop species on wild barley (Hordeum spontaneum L.), a major weed of wheat (Triticum aestivum L.) in Iran, an experiment was conducted using seedling extract of 20 crop species. Plants were grown to flowering stage in a greenhouse, separated into leaf, stem and roots, dried and ground, for preparing water extract. Plant extract were tested on germination and root growth of wild barley and wheat. Results showed that most crop species reduced wild barley germination and root growth. Species like sugar beet, safflower, sorghum and most legume species showed the highest inhibitory effect. Sunflower, chick pea and chickling pea reduced wild barley growth more than wheat, which showed that there is a potential for weed control in wheat using these species. There is also a cosiderble differences in inhibitory effects of different plant parts. For example in cereal the highest inhibitory related to stem extract while, in pulses all plant parts showed high inhibitory against wild barley. Plants evaluated in this study have the potential to be used for biologically based weed control methods in organic cropping systems.
Rostami S.,Islamic Azad University at Arsanjan |
Kohan L.,Islamic Azad University at Arsanjan |
Mohammadianpanah M.,Shiraz University of Medical Sciences
Gene | Year: 2015
Leptin is an adipocytokine made by fat cells and plays a key role in proliferation, cell survival, migration and immune response. It has a powerful effect on the initiation of puberty and in determining age at menarche. The current study is the first investigation to examine the effect of G-2548A leptin gene polymorphism on the age at menarche and breast cancer susceptibility. This case-control study was performed on 203 patients with breast cancer and 171 healthy women. The leptin genotypes were determined using the PCR-RFLP method and age at menarche was obtained by questionnaires. There was a significant difference between the leptin G-2548A genotypes between case and control groups (P<. 0.05). AA genotype is significantly higher in patients compared to the controls. Furthermore, women carrying the AA genotype had a significantly younger age at menarche (12.47. years) than women with the AG (12.94. years) and GG (13.47. years) genotypes. Also, we found that the AA genotype frequency in women with age at menarche <. 13. years was higher than in women with age at menarche ≥. 13. years (OR: 3.4, 95% CI: 1.7-6.7, P: 0.001). In conclusion, the G-2548A leptin gene polymorphism has an important role in the onset of menarche and breast cancer susceptibility. © 2014 Elsevier B.V.