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Assareh E.,Islamic Azad University at Dezful | Poultangari I.,Islamic Azad University at Dezful | Tandis E.,University of Jundi Shapor | Nedaei M.,Islamic Azad University at Tehran
Journal of Mechanical Science and Technology | Year: 2016

Enhancing the energy production from wind power in low-wind areas has always been a fundamental subject of research in the field of wind energy industry. In the first phase of this research, an initial investigation was performed to evaluate the potential of wind in south west of Iran. The initial results indicate that the wind potential in the studied location is not sufficient enough and therefore the investigated region is identified as a low wind speed area. In the second part of this study, an advanced optimization model was presented to regulate the torque in the wind generators. For this primary purpose, the torque of wind turbine is adjusted using a Proportional and integral (PI) control system so that at lower speeds of the wind, the power generated by generator is enhanced significantly. The proposed model uses the RBF neural network to adjust the net obtained gains of the PI controller for the purpose of acquiring the utmost electricity which is produced through the generator. Furthermore, in order to edify and instruct the neural network, the optimal data set is obtained by a Hybrid genetic algorithm along with a gravitational search algorithm (HGA-GSA). The proposed method is evaluated by using a 5MW wind turbine manufactured by National Renewable Energy Laboratory (NREL). Final results of this study are indicative of the satisfactory and successful performance of the proposed investigated model. © 2016, The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.


Khodadadi S.,University of Mazandaran | Ghanavati A.,University of Mazandaran | Assari M.R.,University of Jundi Shapor | Hatami M.,Esfarayen University of Technology | Ganji D.D.,University of Mazandaran
Journal of Mechanical Science and Technology | Year: 2015

An experimental study is conducted on the heat transfer in the reservoir of a solar water-heater flat-plate solar collector to obtain its temperature distribution. A total of 29 temperature sensors are placed inside the reservoir, and 2 sensors in the water inlet and outlet passages. The effect of the inlet and outlet positions on the temperature distribution inside the reservoir is studied to obtain the best location for the maximum temperature range. When the inlet position is II and the outlet position is B (Fig. 3(c)), the reservoir exhibits the best performance because of the high temperature range and areas inside it. © 2015, The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.


Assari M.R.,University of Jundi Shapor | Basirat Tabrizi H.,Amirkabir University of Technology | Najafpour E.,Islamic Azad University at Dezful
International Journal of Thermal Sciences | Year: 2013

Energy and exergy analysis for batch fluidized bed dryer based on the Eulerian two-fluid model (TFM) is performed to optimize the input and output and keep the quality of products in good condition. The two-fluid model is used based on a continuum assumption of each phase. Two sets of conservation equations are applied for gas-solid phases and are considered as interpenetrating continuum. Further this study considers the two-dimensional, axis-symmetrical cylindrical energy and exergy equations for both phases and numerical simulation is preformed. The governing equations are discretized using a finite volume method with local grid refinement near the wall and inlet. The effects of parameters such as: the inlet gas velocity, inlet gas temperature and the particle size diameter on the energy, exergy efficiencies and the availability of gas are sought. Two-fluid model prediction indicates good agreement between the available experimental results and reported non-dimensional correlations and other model predictions. It is illustrated that at the beginning of the drying process, the energy efficiency is higher than the exergy efficiency for a very short time. However two efficiencies come closer to each other at the final stage of the drying. Increasing particle size will decrease both efficiencies and the gas availability at the starting process. © 2012 Elsevier Masson SAS. All rights reserved.


Assari M.R.,University of Jundi Shapor | Basirat Tabrizi H.,Amirkabir University of Technology | Najafpour E.,Payame Noor University | Ahmadi A.,Islamic Azad University at Masjed Soleyman | Jafari I.,Islamic Azad University at Dezful
Thermal Science | Year: 2014

Pulp and paper production industries are known as a renewable energy technology. In this research, exergetic analysis of pulp and paper production is presented. The system performance is evaluated based on the data of Pars paper industrial group, Iran, which is given as an illustrative example. An exergy destruction as well as exergy efficiency relation is determined for each section of the system components and the whole system to indicate the largest exergy losses and possibilities of improvement. It is found that the largest exergy losses occurred in the steam plant and soda recovery and these sections are highly exergy inefficient. Further it is observed that with decrease of excess air and preheating of inlet air the exergy efficiency of boilers is increased.


Assari M.R.,University of Jundi Shapor | Basirat Tabrizi H.,Amirkabir University of Technology | Jafari I.,Islamic Azad University at Dezful
Solar Energy | Year: 2011

Experimental data indicate that high temperature and high performance can be obtained using dual purpose solar collector (DPSC) compared to single water or air collector. A mathematical model based on effectiveness method has been developed for the investigation of thermal performance of DPSC. In the collector two fluids (water and air) flow simultaneously. Three different kinds of channels are used to enhance the performance of collector, such as: rectangular fin, triangular fin and without fin. Simulation results show that channels with rectangular fin have better performance compared with others. The effect of water inlet temperature and air flow rate on heat delivery by air and water has been investigated. © 2011 Elsevier Ltd.


Khorami N.,University of Tehran | Malmasi A.,University of Tehran | Zakeri S.,Pasteur Institute of Iran | Salehi T.Z.,University of Tehran | And 3 more authors.
Comparative Clinical Pathology | Year: 2010

The aim of this study was to determine the utility of urinalysis and dipstick results in predicting leptospiruria in dogs. Ninety dogs, regardless of health status, were included in this study since January to August 2008. All the dogs went through a complete physical examination, and urine samples were collected by catheter or by cystocentesis. Polymerase chain reaction (PCR) testing was performed on urine samples to detect leptospiral DNA. Urinalysis was done at the same time. Of the 90 dogs included in the study, 28 (31%) were diagnosed as shedding leptospires in their urine. In terms of urinalysis test results, no significant difference was found between dogs with or without leptospiruria. Indeed, most of the dogs with positive PCR assay had normal urinalysis findings. The present study suggests that using urinalysis or dipstick is not recommended for screening the dogs that are actively shedding leptospires in their urine. © 2009 Springer-Verlag London Limited.


Nematollahi O.,Isfahan University of Technology | Alamdari P.,Isfahan University of Technology | Assari M.R.,University of Jundi Shapor
Energy Conversion and Management | Year: 2014

In this study, a dual purpose water and air heating system is experimentally investigated. The system consists of a dual purpose flat solar collector and a vertical water storage tank. Water and air have natural and forced convection in the collector, respectively. The reason why dual purpose systems are used is to achieve greater efficiency and lower heat dissipation. Furthermore, high temperature and high performance can be obtained using this solar collector. These systems can be used to heat water and air simultaneously or separately. The hot water can be utilized for domestic applications or as a PCM material for heating air through the night. Besides, the hot air can be used in air conditioning systems, industrial processes and dryers. Therefore, using these collectors brings high energy savings. Absorber plate temperature variation, storage tank average temperature, system efficiency and air velocity effects are presented. Moreover, hourly efficiency is compared for single purpose and dual purpose systems. The results indicate that the efficiency of the dual purpose system is 3 to 5% higher than a single purpose system. © 2013 Elsevier Ltd. All rights reserved.


Tandis E.,University of Jundi Shapor | Assareh E.,Islamic Azad University at Dezful
Engineering with Computers | Year: 2016

The solutions for inverse shape design (ISD) problems are provided in many cases using evolutionary algorithms linked up with CFD solvers. Among the optimization methods, evolutionary algorithms have many advantages, especially in stability, but they usually need a large number of function evaluations. This can be more important as evaluation of cost function requires flow solution which is usually a time-consuming process. This paper presents a new population-based hybrid algorithm called genetic-based bees algorithm (GBBA) as a solution to ISD problems. This method uses crossover and neighborhood searching operators derived from, respectively, genetic algorithm (GA) and bees algorithm (BA) to provide a method with good performance in accuracy and speed convergence. Three test cases have been used to compare the performance of the proposed hybrid algorithm with GA and BA. Here, both ideal and viscose flow solvers are involved to solve flow equations in the physical domain. PARSEC and Bezier are two shape definition methods used for surface modification in these cases. The results show that the final shape obtained by the proposed hybrid algorithm is more accurate compared to either BA or GA. Furthermore, speed convergence increases when GBBA is employed. © 2016 Springer-Verlag London

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