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Kordkheili H.Y.,Islamic Azad University at Sari | Hiziroglu S.,Oklahoma State University | Farsi M.,Islamic Azad University at Sari
Materials and Design | Year: 2012

The objective of this investigation was to evaluate physical and mechanical properties of experimental cement type panels made from multi-wall carbon nanotubes (MWCNTs) and bagasse fiber. Three levels of MWCNTs, namely 0.5. wt.%, 1. wt.% and 1.5. wt.% were mixed with 10. wt.% and 20 wt.% of bagasse fiber in rotary type mixer. Thickness swelling, water absorption, bending characteristics and impact strength of the samples were evaluated. Based on the findings in this work the water absorption and thickness swelling of the nanocomposites decreased with increasing amount of the multi-wall carbon nanotubes content in the panels from 0.5% to 1.5%. On the other hand flexural modulus and impact strength of the panels were enhanced with increased percentage of carbon nanotubes. Panels having 0.5% MWCNTs exhibited the highest impact strength. Overall dimensional stability and strength properties of the samples were adversely influenced with increased amount bagasse fiber in the samples. It appears that using lower percentage of bagasse fiber or application of heat or chemical treatment to the raw material should be considered to improve negative influence of bagasse fiber on properties of the panels. © 2011 Elsevier Ltd.


Nozari K.,Islamic Azad University at Sari | Pedram P.,Islamic Azad University at Tehran
Europhysics Letters | Year: 2010

In this paper we study the effects of the Generalized Uncertainty Principle (GUP) on the spectrum of a particle that is bouncing vertically and elastically on a smooth reflecting floor in the Earth's gravitational field (a quantum bouncer). We calculate energy levels and corresponding wave functions of this system in terms of the GUP parameter. We compare the outcomes of our study with the results obtained from elementary quantum mechanics. A potential application of the present study is discussed finally. Copyright © EPLA, 2010.


Yang X.-S.,University of Cambridge | Hosseini S.S.S.,Islamic Azad University at Sari | Gandomi A.H.,Islamic Azad University at Tehran
Applied Soft Computing Journal | Year: 2012

The growing costs of fuel and operation of power generating units warrant improvement of optimization methodologies for economic dispatch (ED) problems. The practical ED problems have non-convex objective functions with equality and inequality constraints that make it much harder to find the global optimum using any mathematical algorithms. Modern optimization algorithms are often meta-heuristic, and they are very promising in solving nonlinear programming problems. This paper presents a novel approach to determining the feasible optimal solution of the ED problems using the recently developed Firefly Algorithm (FA). Many nonlinear characteristics of power generators, and their operational constraints, such as generation limitations, prohibited operating zones, ramp rate limits, transmission loss, and nonlinear cost functions, were all contemplated for practical operation. To demonstrate the efficiency and applicability of the proposed method, we study four ED test systems having non-convex solution spaces and compared with some of the most recently published ED solution methods. The results of this study show that the proposed FA is able to find more economical loads than those determined by other methods. This algorithm is considered to be a promising alternative algorithm for solving the ED problems in practical power systems. © 2011 Elsevier B.V. All rights reserved.


Kordkheili H.Y.,Islamic Azad University at Sari | Farsi M.,Islamic Azad University at Sari | Rezazadeh Z.,Sari University of Agricultural Sciences and Natural Resources
Composites Part B: Engineering | Year: 2013

The objective of this investigation was to evaluate physical, mechanical and morphological properties of experimental polymer type panels made from single-wall carbon nanotube (SWCNT) and wood flour. The composites with different SWCNTs (0, 1, 2, 3 phc) and maleic anhydride grafted polyethylene (MAPE) (0 and 3 phc) contents were mixed by melt compounding in an internal mixer and then the composites manufactured by injection molding method. The mass ratio of the wood flour to LDPE was 50/50 (w/w) in all compounds. Water absorption, thickness swelling, bending characteristics, impact strength and morphological properties of the manufactured composites were evaluated. Based on the findings in this work the water absorption and thickness swelling of the nanocomposites decreased with increasing with amount of the SWCNTs (from 1 to 3 phc) and MAPE (3 phc) in the panels. The mechanical properties of LDPE/wood-flour composites could be significantly enhanced with increased percentage of MAPE and SWCNTs content. Panels having 2 phc SWCNTs and 3 phc MAPE exhibited the highest impact strength value. Also Scanning Electron Microscope (SEM) micrographs showed that carbon nanotubes can fill the voids of wood plastic composites as well as addition of MAPE and SWCNTs enhanced interaction between the components. © 2012 Published by Elsevier Ltd.


Farsi M.,Islamic Azad University at Sari
Journal of Reinforced Plastics and Composites | Year: 2010

This study deals with the effect of chemical modification of wood flour by components including alkaline, silane, acrylic acid and benzoyl chloride, and PP-g-MA coupling agent concentration (0 and 3 wt%) on the mechanical performance of WPCs. The samples were fabricated by melt compounding in an internal mixer and then injection molding. Tensile, flexural, and Izod impact test of modified composites were performed and compared by net polypropylene and unmodified samples. The results showed that the highest tensile and flexural resistance was observed in composites modified with alkaline and including coupling agent. Modified composites had lower impact strength than unmodified ones. Simultaneous use of chemical modification and coupling agent on mechanical properties had synergic effect. Therefore, chemical modification of wood flour improved interfacial adhesion and so increased the mechanical performance of these composites. © 2010 The Author(s).


Darvishi Khezri H.,Islamic Azad University at Sari
Saudi journal of kidney diseases and transplantation : an official publication of the Saudi Center for Organ Transplantation, Saudi Arabia | Year: 2014

Poor sleep quality is a common problem that can potentially predict mortality risk and quality of life in hemodialysis (HD) patients. Also, inflammation is a common feature in HD patients. To determine sleep quality and its correlation with serum C-reactive protein (CRP) level in these patients, we studied 132 chronic HD patients in two university-affiliated teaching hospitals in Sari, Iran during September 2010. Pittsburgh Sleep Quality Index was employed to assess the sleep quality of the patients in addition to CRP, albumin, cholesterol, phosphorus and hemoglobin levels. There were 104 (78.7%) patients who suffered from poor sleep quality. A significant correlation was found between serum CRP level and the patients' sleep quality (P <0.05). There was also a significant correlation between sleep quality and serum phosphorus and albumin levels and body mass index (P <0.05). Furthermore, a significant positive correlation existed between the different components of sleep quality and CRP (P <0.05). We conclude that there is a correlation between decreased sleep quality in HD patients and elevated CRP levels, which may have therapeutic implications.


Farsi M.,Islamic Azad University at Sari
Fibers and Polymers | Year: 2012

The objective of this investigation was to evaluate the mechanical, thermal stability and viscoelastic behaviors of experimental PP composites made from wheat straw and PP-g-MA coupling agent. Four levels of wheat straw, 10, 20, 25 and 30 wt % and two levels of coupling agent, 0 and 3 % wt were mixed with PP in rotary type mixer and injection molding process, respectively. Tensile characteristics and impact strength, thermal gravity and dynamic mechanical and thermal analysis of the samples were evaluated. Based on the results, it was observed that the tensile properties increased and impact strength decreased with the increase in the fiber loading from 10 % to 30 %. Further, the composites treated with PP-g-MA exhibited improved mechanical properties which confirmed efficient fiber-matrix adhesion. DMT analysis showed that the PP composites made of 30 % wheat straw containing 3 % PP-g-MA showed the highest E' and lowest tan δ than the untreated ones. Also, the thermal stability of wheat straw was lower than PP and as filler content in the composites increased, the thermal stability decreased and the ash content increased. © 2012 The Korean Fiber Society and Springer Netherlands.


Moradi S.E.,Islamic Azad University at Sari
Journal of Industrial and Engineering Chemistry | Year: 2014

Highly ordered mesoporous carbon (OMC) has been prepared and modified with a anionic surfactant sodium dodecyl sulphate (SDS) by microwave heating technique and used as an efficient sorbent for methylene blue (MB) dye removal from wastewater. The structural order and textural properties of the adsorbents was studied by XRD, BET, FT-IR, Raman and TGA analyses. Adsorption experiments were conducted in batch mode with the variables such as amount of adsorbent, agitation speed, contact time, temperature, initial solution concentration and solution pH. The MB dye removal for microwave and impregnation methods modified SDS-OMC and OMC were found to be 95.3, 88.4 and 68%, respectively. © 2013 The Korean Society of Industrial and Engineering Chemistry.


Eshaghi A.,Isfahan University of Technology | Eshaghi A.,Islamic Azad University at Sari
Applied Surface Science | Year: 2012

Cr doped TiO 2-SiO 2 nanostructure thin film on glass substrates was prepared by a sol-gel dip coating process. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the structural and chemical properties of the films. A UV-vis spectrophotometer was used to measure the transmittance spectra of the thin film. The hydrophilicity of the thin film during irradiation and storage in a dark place was measured by a contact angle analyzer. The results indicated that Cr doping has a significant effect on the transmittance and super-hydrophilicity of TiO 2- SiO 2 thin film. © 2011 Elsevier B.V. All rights reserved.


Mollaiy Berneti S.,Islamic Azad University at Sari
International Journal of Computational Intelligence Systems | Year: 2013

In this paper, a novel hybrid approach composed of adaptive neuro-fuzzy inference system (ANFIS) and imperialist competitive algorithm is proposed. The imperialist competitive algorithm (ICA) is used in this methodology to determine the most suitable initial membership functions of the ANFIS. The proposed model combines the global search ability of ICA with local search ability of gradient descent method. To illustrate the suitability and capability of the proposed model, this model is applied to predict oil flow rate of the wells utilizing data set of 31 wells in one of the northern Persian Gulf oil fields of Iran. The data set collected in a three month period for each well from Dec. 2002 to Nov. 2010. For the sake of performance evaluation, the results of the proposed model are compared with the conventional ANFIS model. The results show that the significant improvements are achievable using the proposed model in comparison with the results obtained by conventional ANFIS. © 2013 Copyright the authors.

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