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Hashemi B.,Razi University | Shamsipur M.,Razi University | Seyedzadeh Z.,Academic Center for Education
New Journal of Chemistry | Year: 2016

This work reports the preparation of lithium ionimprinted polymer materials using benzo-12-crown-4 as a selective crown ether, methacrylic acid (MAA) as a functional monomer, ethyleneglycol dimethacrylate (EGDMA) as a crosslinker, and 2,2′-azobisisobutyronitrile (AIBN) as a radical initiator. The imprinted lithium ion was removed from the polymeric matrix using a 1.0 mol L-1 HNO3 solution. The resulting sorbent was characterized using scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) theory, X-ray diffraction (XRD) and IR spectroscopy. The prepared particles have a diameter of 50-60 nm which results in the fast recognition of lithium ions. The maximum adsorption capacity and pre-concentration factor of the prepared particles were 1019.27 μmol g-1 and 100, respectively. The Li+-imprinted sorbent was reused ten times without a significant decrease in binding affinity. The relative standard deviation (RSD%) and the limit of detection were evaluated to be 2.1% and 3.29 μg L-1, respectively. Finally, the resulted IIP particles showed high selectivity toward lithium ions over some foreign metal ions with selectivity coefficients above 18.5. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2016. Source


Shahrezaei F.,Academic Center for Education | Mansouri Y.,Islamic Azad University at Ilam | Zinatizadeh A.A.L.,Razi University | Akhbari A.,Razi University | Akhbari A.,Islamic Azad University at Kermanshah
Powder Technology | Year: 2012

The photocatalytic oxidation and mineralization of petroleum refinery wastewater in aqueous catalyst suspensions of titanium dioxide (TiO 2), Degussa P25 (80% anatase, 20% rutile), were carried out in a batch circulating photocatalytic reactor. The experiments were conducted based on a central composite design (CCD) and analyzed using response surface methodology (RSM). In order to analyze the process, four significant variables viz. pH (2-10), catalyst concentration (0-200mg/l), temperature (22.5-52.5°C), and reaction time (30-150min) and TCOD removal as the process response were studied. From the data derived from the factorial design, the ANOVA analysis revealed that the first-order effects of reaction time, pH, temperature and catalyst concentration and second-order effect of pH, catalyst concentration and temperature produce the main effect on TCOD removal efficiency. A maximum reduction in TCOD of more than 83% was achieved at the optimum conditions (pH of 4, catalyst concentration of 100mg/l, temperature of 45°C and reaction time of 120min). The reaction kinetics showed that reactive activation energy for TCOD conversion was calculated to be 19.34kJ/mol. © 2012 Elsevier B.V. Source


Kashef N.,University of Tehran | Djavid G.E.,Academic Center for Education | Shahbazi S.,University of Tehran
Journal of Infection in Developing Countries | Year: 2010

Background: Antibiotic resistance of urinary tract pathogens has increased worldwide. Knowledge of the antibiotic resistance patterns of uropathogens in specific geographical locations is an important factor for choosing an appropriate empirical antimicrobial treatment. The aim of this study was to provide information regarding local resistance patterns of urinary pathogens to the commonly used antibiotics in Tehran, Iran.Methodology: Urine samples collected and submitted to two pathobiology laboratories in Tehran were identified by conventional methods over a period of three years (December 2006 to May 2009). Antimicrobial resistance testing was performed by the standard disk diffusion technique in accordance with the recommendations of the Clinical and Laboratory Standards Institute.Results: Of the total 13,333 mid-stream urine samples collected from suspected cases of urinary tract infection, 840 (6.3%) were positive for pathogenic bacteria. Escherichia coli (E. coli) was the most common isolate (68.8%) followed by Proteus spp. (12.4%), and Klebsiella spp. (9.6%). E. coli isolates were mostly susceptible to nitrofurantoin (71.3%), followed by ciprofloxacin (68.1%); however, only 38.2% of E. coli isolates were susceptible to trimethoprim-sulfamethoxazole. Conclusion: Nitrofurantoin may be considered as a first-line empiric antibacterial agent for urinary tract infections in outpatients in Tehran, Iran. © 2010 Kashef et al. Source


Iranmanesh A.,Tarbiat Modares University | Kafrani A.S.,Tarbiat Modares University | Khormali O.,Academic Center for Education
Optoelectronics and Advanced Materials, Rapid Communications | Year: 2010

Wiener index was introduced by Harold Wiener in 1947. This index is the sum of distance between all vertices of a graph. The edge versions of Wiener index were introduced by Iranmanesh et al., recently. In this paper, the first edge Wiener index of TUAC6[p,q] nanotube is computed. Source


Mahmiani A.,Islamic Azad University | Khormali O.,Academic Center for Education | Iranmanesh A.,Tarbiat Modares University
Optoelectronics and Advanced Materials, Rapid Communications | Year: 2010

In this paper, the first type of edge-Wiener index of TUC4C8(R) nanotube is computed. Source

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