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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.

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.

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.

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