Islamic Azad University North Tehran Branch

About: Islamic Azad University North Tehran Branch is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Adsorption & Catalysis. The organization has 868 authors who have published 968 publications receiving 9987 citations.

Exergy analysis of NGL recovery plant using a hybrid ACOR‐BP neural network modeling: a case study

Abstract: The major objective of the study is to make exergy analysis of natural gas liquid (NGL) process more understandable by coupling it with the use of an artificial neural network modeling. The presented method permits to provide an energy diagnosis of the process under a wide range of operating conditions. As a case study, Siri Island NGL Recovery in Iran is considered. The Aspen Plus process simulator linked with MATLAB Software was used to obtain thermodynamic properties of the process streams and to perform exergy balances. The results are validated with industrial data. The exergy destruction and exergetic efficiency for the main system components and for the entire system were calculated. Major sources of irreversibility in the process are identified, and the best conditions for process improvement are presented. The simulation results reveal that the exergetic losses of the separation towers, heating/cooling equipment, and compression/expansion section obtain the highest rank among the other components of the plant. The results show that the overall exergetic efficiency of the system is about 61%. After proposing new operational conditions, another exergetic analysis was made that caused a decrease of 6% in the exergetic losses of the entire system. Then, the recorded and calculated data are used as inputs for the neural network. The results show that ACOR is highly effective to optimize the performance of the neural networks to predict overall exergy efficiency. This method was compared with other current methods, and the results indicated that the integrated n Ant Colony Optimization-Back Propagation (ACOR-BP) provides the least error on the testing dataset. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.

Effect of glutathione-stabilized silver nanoparticles on expression of las I and las R of the genes in Pseudomonas aeruginosa strains.

Abstract: Biofilm formation is regarded as a significant factor in the establishment of infections caused by Pseudomonas aeruginosa. P. aeruginosa is one of the most important causes of nosocomial infections. Today silver nanoparticles (Ag-NPs) are used as antimicrobials due to their well-known, chemical, biological, and physical properties. Exposure to nanoparticles could inhibit colonization of new bacteria onto the biofilm. In the present work, the green synthesis of Ag-NPs was performed using the alcoholic extract of Eucalyptus camaldulensis. Ag-NPs and glutathione-stabilized silver nanoparticles (GSH–Ag-NPs) were characterized using X-ray diffraction (XRD), dynamic light scattering (DLS), scanning electron microscope (SEM), and carbon, nitrogen, and hydrogen (CNH) and Fourier transform infrared spectroscopy (FTIR) techniques were applied to investigate the structure of the modified nanoparticles. Then, the antimicrobial and antibiofilm potential of the prepared Ag-NPs and GSH–Ag-NPs against P. aeruginosa strains was evaluated using microbroth dilution method and their effects on the expression of las I and las R genes. In this study, a total of 50 P. aeruginosa isolates were recovered from clinical samples. According to the results, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) value of Ag-NPs against P. aeruginosa was determined to be 512–256 μg/ml, respectively, while the MIC and MBC value of GS–Ag-NPs against P. aeruginosa clinical strains was determined in a range of 128–256 μg/ml and 256–512 μg/ml, respectively. The mean expression level in las R, las I genes in P. aeruginosa strains treated with ½ MIC of Ag-NPs was decreased by −5.7 and −8fold, respectively. The mean expression levels of las R, las I genes in P. aeruginosa strains treated with ½ MIC of GS–Ag-NPs were decreased by −8.7 and −10fold, respectively (P < 0.05). The results of our study showed that Ag-NPs and GS–Ag-NPs are highly effective against P. aeruginosa strains. Moreover, this study also proves the promising potential of using nanoparticles as anti-biofilm formation and antibacterial agents.

Sediment yield and soil erosion assessment by using an empirical model of MPSIAC for Afjeh & Lavarak sub-watersheds, Iran

Abstract: Watershed degradation due to soil erosion and sedimentation is one of the major environmental problems in Iran. With respect to the relatively suitable compatibility of MPSIAC model to the arid and semiarid conditions of Iran and lack of hydrometric station in region, we employed the "modified PSIAC model" to estimating of sediment yield and providing sediment yield map in these sub-watersheds. The MPSIAC method incorporates nine environmental factors that contribute to sediment yield of the watershed, this factors are: surface geology, soil, climate, runoff, topography, ground cover, land use, channel and upland erosion. Open-source Geographic Information System (GIS) was used to facilitate the spatial interpolation of the nine model factors and interpretation of predicted sediment yield for the entire watersheds. At first, to enter the available raw data into the GIS framework we digitized the nine factors of maps. In the second stage, digitized maps were encoded with respect to the values of each factor and then these factors of maps were summed together, and finally sedimentation score map was provided. We applied (QS) equation on the sedimentation score map and finally related map was obtained. Various formations basically contain Shaly, Sandstone, Conglomerate and tuff lithology, covered this region more than igneous rocks. The results show that the most values of erosion are in Shaly, Marly, weathered Tuff and alluvial diposites parts of sub-watersheds correlated with sensitive formations such as Karaj and Quaternary sediments. Based on sediment yield map of MPSIAC model, more than 75% of the total sub-watersheds area was classified at class IV of erosion category with high sedimentation. Sub-basin’s erosion were calculated as 769.3 and 583.21 m2/km3 per year for each Afjeh and Lavarak sub-basins by MPSIAC model, respectively. Linear regression analysis between MPSIAC model results and two of most influencing factors on erosion, the geology and soil erodibility indicated that there was a significant correlation. The results of this paper suggested that the model is suitable for predicting yearly average sediment yield of the Iranian watersheds with similar conditions.

Preparation of human serum albumin nanoparticles using a chemometric technique

Abstract: Human serum albumin (HSA), a versatile protein carrier for drug delivery, is an ideal material to fabricate nanoparticles for drug delivery systems. These nanoparticles can accumulate in tumor interstitium due to the enhanced permeability and retention effect. The most important characteristics of HSA nanoparticles are particle size, shape, and zeta potential. A chemometric approach was applied for HSA nanoparticles’ size optimization in this study. The effects of three experimental parameters; pressure (P) or power, organic solvent volume (V), and time (T), were investigated under sonication and high-pressure homogenization, using multivariate analysis. The trials were performed based on the Box–Behnken experimental design. The criteria for the appraisal of the descriptive ability of a multinomial were R 2 = 0.819, standard error = 20.420, and F-ratio = 19.550. The method was optimized with respect to the nanoparticles’ size as a response. The Box–Behnken experimental design was applied to optimize and trial the robustness of the HSA nanoparticle preparation method.