Islamic Azad University at East Tehran
Tehran, Iran
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Ghiasi R.,Islamic Azad University at East Tehran | Zamani A.,Islamic Azad University at Tehran
Journal of the Chinese Chemical Society | Year: 2017

In this investigation, we describe substituent effect on the dipole moment, ionization potential, electron affinity, structure, frontier orbitals energy, in the trans-Cl(OC)(H3P)3W(≡C-para-C6H4X) (X=H, F, SiH3, CN, NO2, SiMe3, CMe3, NH2, NMe2) complexes using MPW1PW91 quantum chemical calculations. The nature of chemical bond between the [Cl(OC)(H3P)3W]- and [C-para-C6H4X]+ fragments was illustrated with energy decomposition analysis (EDA). Percentage composition in terms of the defined groups of frontier orbitals for these complexes was inspected to investigate the character in metal-ligand bonds. Quantum theory of atoms in molecules (QTAIM) was used for illustration of metal-ligand bonds in these complexes. © 2017 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hossein Ghaderian S.M.,Shahid Beheshti University of Medical Sciences | Najar R.A.,Shahid Beheshti University of Medical Sciences | Tabatabaei Panah A.S.,Islamic Azad University at East Tehran
Molecular Biology Reports | Year: 2011

A polymorphism within tumor necrosis factora (TNF-α) gene promoter and contribution of TNF-α converting enzyme (TACE) have been reported to be associated with TNF-α production which may increase susceptibility to heart failure such as acute myocardial infarction (AMI). However, the relationship between this polymorphism and susceptibility to AMI and the mechanism of TACE-TNF-α system regulation has poorly been studied. Genomic DNA and peripheral blood mononuclear cells (PBMCs) of patients with AMI and control subjects was extracted. The-308 G/A TNF-α polymorphism was detected. The mRNA transcription and protein expression levels of TNF-α and TACE were analyzed by real time RTPCR and flow cytometry respectively as well as plasma TNF-α by ELISA. The 'A' allele frequency of TNF-α was significantly more frequent in the patients than controls (P<0.001). There were statistically significant differences in TNF-α and TACE mRNA and protein levels as well as circulating TNF-α in the patients. However, these levels were higher in the patients who carry 'A' allele. There were significant positive correlation between these mRNAs and protein expression levels (r = 0.66, P<0.001, r = 0.78, P<0.001 respectively). These data suggest that genetic polymorphism in TNF-α might be helpful for determining susceptibility to AMI in Iranian patients. The TACE-TNF-α system in circulating leucocytes is stimulated which these results demonstrate that in patients with AMI, TACE expression in PBMC increases with TNF-α expression and processing of TNF-α in PBMC might be regulated by TACE at transcriptional, translational, and post-translational levels in AMI. © 2011 Springer Science+Business Media B.V.

Refahi Oskouei A.,Islamic Azad University at East Tehran | Heidary H.,Amirkabir University of Technology | Ahmadi M.,Amirkabir University of Technology | Farajpur M.,Islamic Azad University at East Tehran
Materials and Design | Year: 2012

In using acoustic emissions (AEs) for mechanical diagnostics, one major problem is the discrimination of events due to different types of damage occurring during loading of composite materials. Unsupervised pattern recognition analyses (fuzzy c-means clustering) associated with a principal component analysis (PCA) are the tools that are used for the classification of the monitored AE events. Composites at different layups are used with the acoustic emission technique. A cluster analysis of AE data is achieved and the resulting clusters are correlated to the damage mechanisms of the material under investigation. Time domain methods are used to determine new relevant descriptors to be introduced in the classification process to improve the characterization and the discrimination of the damage mechanisms. The results show that there is a good fit between clustering groups and damage mechanisms. Additionally, AE with a clustering procedure are effective tools that provide a better discrimination of damage mechanisms in glass/polyester composite materials. © 2012.

Abbasi M.,Islamic Azad University at East Tehran | Reza Sebzari M.,Iran University of Science and Technology | Mohammadi T.,Islamic Azad University at South Tehran
Chemical Engineering and Technology | Year: 2011

Results of a hybrid microfiltration-powderedactivatedcarbon (MF-PAC) system for the treatment of synthetic oily wastewaters with mullite and mullite-alumina (50% alumina content) ceramic membranes are presented. The experiments were conducted to determine the effects of the presence of PAC on MF process performance in terms of flux decline, membrane fouling, and total organic carbon (TOC) rejection. The experimental results demonstrate that PAC addition at low concentration (200-400ppm) increases permeate flux by 19.6% for mullite and 61% for mullite-alumina MF membranes. However, high PAC concentration (1200ppm) decreases the permeate flux by 22% for mullite and 25% for mullite-alumina MF membranes. Also, TOC rejection increases from 93.8 to 97.4% for mullite and from 89.6 to 92.4% for mullite-alumina MF membranes. The study presented here focuses on efficient treatment of oily wastewaters using mullite and mullite-alumina ceramic membranes in a hybrid microfiltration-powdered activated carbon (MF-PAC) laboratory-scale system. The objectives of this study were to investigate the role of PAC on permeate flux, TOC removal efficiency, and fouling resistance of mullite and mullite-alumina ceramic membranes, and to obtain the optimum PAC concentration. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nikoo M.R.,University of Tehran | Kerachian R.,University of Tehran | Karimi A.,Islamic Azad University at East Tehran | Azadnia A.A.,University of Tehran
Environmental Monitoring and Assessment | Year: 2013

In this paper, a new methodology is developed for integrated allocation of water and waste-loads in river basins utilizing a fuzzy transformation method (FTM). The fuzzy transformation method is used to incorporate the existing uncertainties in model inputs. In the proposed methodology, the FTM, as a simulation model, is utilized in an optimization framework for constructing a fuzzy water and waste-loads allocation model. In addition, economic as well as environmental impacts of water allocation to different water users are considered. For equitable water and waste load allocation, all possible coalition of water users are considered and total benefit of each coalition, which is a fuzzy number, is reallocated to water users who are participating in the coalition. The fuzzy cost savings are reallocated using a fuzzy nucleolus cooperative game and the FTM. As a case study, the Dez River system in south-west of Iran is modeled and analyzed using the methodology developed here. The results show the effectiveness of the methodology in optimal water and waste-loads allocations under uncertainty. © 2012 Springer Science+Business Media B.V.

A simple method has been developed for the preconcentration of mercury based on the adsorption of its Schiff's base diphenylthiocarbazone (DPC)complex on a silica gel-immobilized Schiff's base diphenylthiocarbazone (DPC)column.The influence of acidity, eluting agents, stability of the column, sample volume and interfering ions has been investigated in detail. The adsorbed complex could be' eluted using environmentally benign polyethylene glycol (PEG 400) and the concentration of mercury was determined by visible spectrophotometry at a wavelength maximum of 535 nm. A detection limit of 5 ugL ' could be achieved and the developed procedure was successfully applied for the determination of mercury in spiked water samples. The preconcentration factor attainable for quantitative recovery (>96%) of mercury(II) was 100 for a 1000mL sample volume.

Poursharifi M.J.,Islamic Azad University at Sāveh | Moghimi A.,Islamic Azad University at East Tehran
Asian Journal of Chemistry | Year: 2011

A new approach for a cloud point extraction electrothermal atomic absorption spectrometric method was used for determining bismuth. The aqueous analyte was acidified with sulfuric acid (pH 3.0-3.5). Triton X-114 was added as a surfactant and sodium diethyldithiocarbamate was used as a complexing agent. After phase separation at 50 °C based on the cloud point separation of the mixture, the surfactantrich phasewas diluted using tetrahydrofuran. Twenty microliters of the enriched solution and 10 μL of 0.1 % (w/v) Pd(NO 3) 2 as chemical modifier were dispersed into the graphite tube and the analyte determined by electrothermal atomic absorption spectrometry. After optimizing extraction conditions and instrumental parameters, a preconcentration factor of 195 was obtained for a sample of only 10 mL. The detection limit was 0.04 ng mL -1 and the analytical curve was linear for the concentration range of 0.04-0.70 ng mL -1. Relative standard deviations were < 5 %. The method was successfully applied for the extraction and determination of bismuth in samples water.

Mostofi M.,Islamic Azad University at East Tehran | Nosrat A.H.,Queen's University | Pearce J.M.,Queen's University
International Journal of Environmental Science and Technology | Year: 2011

Due to the negative environmental effects of fossil fuel combustion, there is a growing interest in both improved efficiency in energy management and a large-scale transition to renewable energy systems. Using both of these strategies, a large institutional-scale hybrid energy system is proposed here, which incorporates both solar photovoltaic energy conversion to supply renewable energy and cogeneration to improve efficiency. In this case, the photovoltaic reduces the run time for the cogeneration to meet load, particularly in peaking air conditioning times. In turn, however, the cogeneration system is used to provide power back up for the photovoltaic during the night and adverse weather conditions. To illustrate the operational symbiosis between these two technical systems, this study provides a case study of a hybrid photovoltaic and cogeration system for the Taleghani hospital in Tehran. Three design scenarios using only existing technologies for such a hybrid system are considered here:1) single cogeneration + photovoltaic, 2) double cogeneration + photovoltaic, 3) single cogeneration + photovoltaic + storage. Numerical simulations for photovoltaic and cogeneration performance both before and after incorporating improved thermal energy management and high efficiency lighting were considered. The results show that the total amount of natural gas required to provide for the hospitals needs could be lowered from the current status by 55% for scenario 1 and 62% for both scenarios 2 and 3, respectively. This significant improvement in natural gas consumption illustrates the potential of hybridizing solar photovoltaic systems and cogeneration systems on a large scale. © IRSEN, CEERS, IAU.

Haghparast M.,Islamic Azad University at East Tehran
Ships and Offshore Structures | Year: 2016

In magnetohydrodynamic (MHD) seawater thrusters, a lot of energy is stored in the superconducting coil which produces the magnetic field. Although it is necessary to store this energy in the field coil to produce a constant thrust, on the way back to the beach and before mooring, this energy can be used to supply the required electricity of the ship equipment. This will lead to consumption of the field coil energy and will reduce the magnetic field intensity in the channel with a decaying exponential function. In this study, an approximate analytical solution is presented to predict the transient behaviour of the MHD thruster with decaying exponential magnetic field. Using this analysis, the maximum navigable distance and the maximum speed of a hypothetical MHD vessel are calculated as a function of Stuart number, electromagnetic interaction number, Reynolds number, and the time constant. The results show that the electromagnetic parameter and the Stuart number can be considered as measures of electromotive and counter-electromotive forces of the MHD thruster, respectively. These two parameters are the most important factors in increasing and decreasing the maximum navigable distance of the MHD vessel. © 2016 Informa UK Limited, trading as Taylor & Francis Group

Aghabeygi S.,Islamic Azad University at East Tehran | Bigdeli F.,Payame Noor University | Morsali A.,Tarbiat Modares University
Journal of Inorganic and Organometallic Polymers and Materials | Year: 2012

Two zinc(II) coordination polymers, {[Zn(3-bpdb)(NO 2)]·0. 5H 2O} n (1) and [Zn(4-bpdb)(NO 2) 2] n (2), 3-bpdb = 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene and 4-bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene}, have been synthesized and characterized by elemental analyses and IR spectroscopy. Nanoparticles of zinc(II) oxide have been prepared by thermolyses of two different zinc(II) coordination polymers, 1-2. The nano-materials were characterized by scanning electron microscopy, X-ray powder diffraction and IR spectroscopy. The thermal stability of ZnO nano-particles was studied by thermal gravimetric and differential thermal analysis and showed that there is no loss of weight, which indicates that the products were zinc(II) oxide. This study demonstrates the coordination polymers may be suitable precursors for the preparation of nanoscale materials. © 2011 Springer Science+Business Media, LLC.

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