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Shahi M.,Semnan University | Shahi M.,Water and Waste Water Company | Mahmoudi A.H.,Semnan University | Talebi F.,Semnan University
Heat Transfer Research | Year: 2012

The objective of this paper is to investigate the natural convection cooling of a heat source mounted inside a square cavity with special attention being paid to entropy generation. The cavity is filled with copper-water nanofluid; the right vertical wall is kept at a constant temperature, while other walls are adiabatic ones. The numerical scheme is based on the finite volume method with the SIMPLE algorithm for pressure-velocity coupling. In this study, the influence of some effective parameters such as the Rayleigh number, location of the heat source, and solid concentration are studied; then, entropy generation due to the heat transfer irreversibility and fluid friction irreversibility as a function of Ra and solid concentration and heat source location is studied. The result shows that location of the heat source is an important parameter affecting the flow pattern and temperature field and variation of the entropy generation. Consequently the optimum case is selected since the thermal system could have the least entropy generation and the best heat transfer rate. © 2012 by Begell House, Inc.

Soroush F.,Isfahan University of Technology | Mousavi S.F.,Isfahan University of Technology | Gharechahi A.,Water and Waste Water Company
Iranian Journal of Science and Technology, Transaction B: Engineering | Year: 2011

Fuzzy logic provides an effective tool for classifying water quality in a river system based on limited observations. In this study, a fuzzy index (range of 0-100) is proposed for evaluation of water quality for industrial uses. Fuzzy inference system makes it possible to combine the certainty levels for the acceptability of water based on a prescribed limit of various regulatory bodies' quality classes and expert opinions. Application of the proposed fuzzy index is demonstrated with a case study for the Zayandehrud River, located in Isfahan province, Iran. A data set on nine sampling stations along this river was used. Water quality was evaluated for industrial purposes by means of six parameters (pH, TH, TA, SO 4 2-, Cl - and TDS). The results showed that during the study period, the water quality of the river was suitable for some industrial purposes except in Varzaneh. In this station, Zayandehrud receives wastewater of some small industries and agricultural lands. The water quality degraded from Pole Kalleh (index value of 90) to Varzaneh (index value of 15) in the winter months. In the summer months, the index was variable for these two stations. The proposed approach exhibits a convenient tool for continuous monitoring of river water for industrial purposes. © Shiraz University.

Fouda A.S.,Mansoura University | Rashwan S.M.,Suez Canal University | Abo-Mosallam H.A.,Water and Waste Water Company
Desalination and Water Treatment | Year: 2013

The inhibitive and adsorptive characteristics of ethanol extract of fennel seeds for the corrosion of 304 stainless steel (SS) in 1 M HCl solutions have been studied using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy, and electrochemical frequency modulation methods for monitoring corrosion. Ethanol extract of fennel is a good adsorption inhibitor for the corrosion of 304 SS in HCl. The inhibitive property of the extract is attributed to the presence of anethol and fenchone as major constituents in the extract. Inhibition efficiency increased with increasing concentration of the extract but decreased by increasing the temperature. Adsorption studies revealed that Langmuir adsorption isotherm is the best adsorption model applicable to the adsorption of fennel extract on 304 SS surface. Activation and adsorption parameters were evaluated and discussed. Potentiodynamic polarization measurements indicated that the inhibitor is of mixed type. The results obtained from these techniques were in good agreement to prove the validity of these tools in the measurements of the tested inhibitor. © 2013 Copyright Balaban Desalination Publications.

Fouda A.E.-A.S.,Mansoura University | Nazeer A.A.,National Research Center of Egypt | El-Khateeb A.Y.,Mansoura University | Fakih M.,Water and Waste Water Company
Journal of the Korean Chemical Society | Year: 2014

The inhibition effect of cinnamon plant extract as a green corrosion inhibitor for steel in sulfide polluted salt water was studied by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM). The results showed that cinnamon plant extract in sulfide polluted salt water is a good corrosion inhibitor with inhibition efficiency reached to 80% at 250 ppm of the plant extract. The adsorption of cinnamon obeys Temkin adsorption isotherm, and acts as a mixed-type of inhibitor but dominantly as a cathodic inhibitor in sulfide polluted salt water.

Kheiri R.,Alborz Province Water and Waste Water Company | Kheiri R.,Water and Waste Water Company | Mostaghim M.,Water and Waste Water Company
Advances in Environmental Biology | Year: 2013

A selectively enriching medium and octaplex PCR were developed for direct and sensitive detection of 8 specific genes of coliforms/Escherichia coli in water samples within 24 h. Genes traced by octaplex PCR include 16S rRNA, phoE, mdh, gadA/B, lacZ, uidA, cadA and tnaOP, yielding 348, 392, 544, 670, 876, 1700, 2000 and 3065 bp PCR products, respectively. In this study we tested and compared 5235 water samples both by current approach and standard method 9221 D. Results gained confirmed molecular (genetical) approaches are more specific and sensitive rather than the laborious and time consuming biochemical approaches.

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