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.

Preparation of ZnO nanoparticles using Tragopogon Collinus leaf extract and study of its antibacterial effects for therapeutic applications

Abstract: Green synthesis is a well-known technique for the preparation of nanoparticles because it is simple, low-cost, nontoxic, and environmentally friendly. In this research, “Tragopogon collinus” extract was used for synthesis of zinc oxide nanoparticles and their antibacterial effects were studied. Based on this, the extract of the plant was prepared and the synthesis of ZnO nanoparticles under different conditions such as pH of the solution, quantity of extract, temperature, and concentration of the zinc ions precursor were investigated. The best conditions for the synthesis of the nanoparticles was 0.05 M of zinc acetate dihydrate solution, temperature of 80 °C, pH = 12 and 1 cc of the extract, which the formation of the nano particles was confirmed by UV–Vis, TEM, XRD, FT-IR analysis. Average particle size of the prepared ZnO was obtained 21 nm and the nanoparticles have a rod-like structure with spherical masses. The synthesized ZnO nanoparticles showed inhibition zone for both Gram-positive and -negative bacteria and Staphylococcus aureus has better result compared to Escherichia coli.

The Presentation of Financial Crisis Forecast Pattern (Evidence from Tehran Stock Exchange)

Abstract: The purpose of this study is presenting a model for forecasting financial crisis in Tehran Stock Exchange listed companies. To do this, productive firms that had accepted in Tehran Stock Exchange between 2002 and 2009, were selected as the study sample. First the independent variables were obtained based on financial ratios and then based on Article 141 of the Co mmerce Law, the insolvent and solvent firms were separated. Next , based on these two groups of firms, the presence or absence of meaningful d ifference between independent variables (financial ratios) of this two groups samples were tested. The results obtained fro m this test contributed to the ext raction of a proper model of forecast using logistic regression. The results indicated that the variables of debt to the equity ratio, net profit to net sales ratio & working capital to assets ratio were identified as independent variables in the final model. In addition, the results indicated that using the test data, the forecast strength of the model is 81.49%, its degree of sensitivity is 96.12% and its degree of identification is 67.48%.

The effects of magnetic fields on growth and enzyme activities of helianthus annuus l. seedlings

Abstract: In recent years, many research studies have been conducted on the effects of magnetic field on plants. But certain mechanisms regarding magnetic influences have not been defined yet. In this study, effects of magnetic fields (MF) on the growth parameters and enzyme activities of Helianthus annuus L. were investigated. Sterilized seeds in sterile conditions were exposed to 0, 0.5, 1 and 1.5 mT of MF. One day after the treatments percentage of seed germination was increased at 0.5 mT. Different MF densities had no significant effects on root length and fresh weight of leaves. The highest level of shoot length was gained at 1 mT. In this treatment the activity of auxin oxidase was significantly decreased compared with that of the control samples. The activity of the catalase and peroxidase were decreased by MF. The minimum level of protein content and catalase and peroxidase activity were observed in the samples exposed to 1 mT of MF while there were no significant differences in the ascorbate peroxidase activity of different treatments. MF caused a reduction in chlorophyll a, b in all treatments compared to the control. The Results confirmed that the intensity of the MF had different effects on the growth parameters and enzyme activity.

Socioeconomic Impact Assessment of Deforestation of Hyrcanian Forests on Local Communities

Abstract: The present study was conducted to assess socio-economic impacts of deforestation of Hyrcanian forests in two basins of Do-Hezar and Se-Hezar, northern Iran. To this end, changes in the forest area were detected over the period between 1990 and 2006 based on land use land cover maps derived from Landsat and IRS satellite images. The land use changes were investigated by enhancement of the images at each time interval. The Normalized Difference Vegetation Index (NDVI) was also used to evaluate the density of the land cover in the form of six greenness classes. Subsequently, the socioeconomic impacts of deforestation in the basins were estimated using rapid assessment matrix. Depending on the extent of destruction, the socioeconomic parameters affected by destroyed or decreased forest area were identified and scored by RIAM Software. The obtained results indicated that the greatest changes in forest area was occurred due to urban development and expanded farmland areas within over years 2000-2006, when the greenness degree was also decreased. Acceding to the RIAM results, 3% of the deforestation impacts in two basins was very negative (-E) while, 23% was moderately negative (-c). Besides, slightly negative (-A) impacts include 27% of the total negative effects. Although the adverse effects of deforestation on socioeconomic status of the residents were not very destructive, however, the impacts on the rural community could be important and noticeable.

Bis(propane-1,2-diammonium) benzene-1,2,4,5-tetra-carboxyl-ate dihydrate.

Abstract: In the crystal of the title hydrated molecular salt, 2C(3)H(12)N(2) (2+)·C(10)H(2)O(8) (4-)·2H(2)O, the packing is stabilized by extensive N-H⋯O and O-H⋯O hydrogen-bonding inter-actions involving all three species, forming a supra-molecular three-dimensional structure. The tetraanion is generated by inversion.