mostafa fazli

Ferula latisecta, Dorema kopetdaghense, and Dorema ammoniacum oleo-gum resins are among the most valuable Iranian herbal products and have great potential to be exported abroad. This study aims to phytochemically investigate the antioxidant and antidiabetic effects of the mentioned oleo-gum resins. The hexane, ethyl acetate, and methanolic extracts of gums were prepared through a "sequential extraction" method. The antidiabetic effects of the extracts were evaluated on the basis of α-amylase and α-glycosidase enzyme inhibition methods. In addition, the antioxidant effects of the extracts were analyzed against DPPH free radicals. Besides, the phenolic and flavonoid compounds of the extracts were measured. The results showed that the hexane extract of D. ammoniacum gum had the highest inhibitory activity against α-glucosidase (92.99%). Also, the methanolic extract of this plant showed the highest inhibitory activity against α-amylase (50.84%). The hexane extract of D. ammoniacum gum has high antioxidant properties with an IC50 value of 40.85 μg/mL. Moreover, the hexane extract of D. ammoniacum gum has the highest amount of phenolic compounds with 530.52 mg of gallic acid/g of extract, among the others. According to the results, the gum of D. ammoniacum is rich of phenolic compounds and has high antioxidant and antidiabetic effects in comparison to common standards. So, this herbal product can be worthy of further investigation.

In this study, ZnO/TiO_2 : Ag composite fibers were prepared by a simple stretching method. The prepared fiber nanocomposites' structural, optical and photocatalytic properties were investigated. X-ray diffraction (XRD) results showed that the structure was successfully synthesized. Scanning electron microscopy (SEM) images showed that the diameter of the prepared fibers was about 10 micrometers. Fourier transform infrared (FTIR) spectroscopy and EDX energy scattering confirmed the strong bonds of the relevant elements and their presence in the composite structure. Increasing the calcination temperature improved the structure and purity of the composite. The photocatalytic performance of nanofiber composites for the degradation color of methylene blue (MB) under UVA light was studied. It was observed that the prepared nanofibers have suitable physical-optical properties and photocatalyst properties (98%) under UVA light exposure in 100 min for the treatment of industrial wastewater containing dyes.

La0.7Ca0.3MnO3 (LCMO) powder was synthesized via the hydrothermal method. Structural, morphological, and optical properties of the as-prepared sample were systematically characterized. The XRD results proved the existence of only one crystalline phase. The FESEM image indicates that the La0.7Ca0.3MnO3 sample has a nanorod structure with an average diameter of approximately 125 nm. According to UV-Vis analysis, the band gap energy of the sample was estimated about 2.13 eV. The adsorption and photocatalytic performances of LCMO nanostructure were systematically characterized. The photoactivity efficiency for decolorizing Rhodamine B solution (10 ppm), by LCMO (0.5 g/L), with nearly 80 min illumination, was more than 90% with a reaction rate constant of 0.029 min−1. Ultimately, the reusability of the photocatalyst for degrading the RhB dye was investigated using six cycles. The good reusability and stability of LCMO implies a potential application for dealing with high-concentration dyes by adsorption–photocatalytic degradation.

The adsorption of carbon dioxide molecules on four H-saturated porous graphene sheets with different pore sizes and a poreless graphene sheet was investigated and compared with the adsorption of nitrogen molecules on them. Reactive molecular dynamics was used in this study, which took into account the possibility of chemical bond formation and dissociation as well as the effects of polarity. This research demonstrates that all porous graphene sheets and non-cavity graphene sheets absorb carbon dioxide molecules more than nitrogen molecules and can be used to separate these two gases. However, the size and shape of the cavities have no significant impact on gas molecule adsorption on these plates.

In this research, it has been tried to construct a self-healing epoxy based nanocomposite using montmorillonite (MMT) nanoparticles. Urea-formaldehyde microcapsules were made using in-situ polymerization in the presence of Montmorillonite nanoparticles and MMT modified microcapsules were studied using FT-IR and optical microscopy (OM). The analyzes showed that the use of montmorillonite was effective in the preparation of microcapsules and improved their properties. Finally, the epoxy based self-healing nanocomposite was made using MMT nanofiller and DCPD healing agent. Finally thermal stability of self-healing nanocomposite reinforced with clay nanoparticles was investigated using thermal gravimetery analysis as well as mechanical strength before and after damage.

Two different possible mechanisms of water gas shift reaction including formate and redox mechanisms on the Ag5 cluster were investigated using DFT computations. All the elementary steps involved in both mechanisms were considered. It was observed that dissociation of H2Oads and OHads, as well as formation of CO2(ads), required activation energy. For these steps, transition state structures were determined and their corresponding activation energies were calculated. For both mechanisms, the highest activation energy (402.34 kJ mol-1) was related to the dissociation of OHads as the rate limiting step. The calculated activation energy of CO2(ads) formation according to the redox mechanism (COads + O ads → CO2(ads)) was 9.32 kJ mol-1 indicating that this step was relatively fast on the surface of Ag5 cluster. It was observed that, CO2(ads) formation according to the formate mechanism occurred through three consecutive steps where the dissociation of formate (HCOO(ads) → CO2(ads) + Hads) had the highest activation energy, 171.53 kJ mol-1.

In this study, the interaction of Schiff base Exo-Vanadium Complexes from salicylidine derivatives with cytomegalovirus DNA (ct-DNA) was investigated by ultraviolet-spectroscopy and fluorescence spectroscopy. Using the results of these empirical studies, the coupling mechanism between the two chlorine derivatives and the bromo derivative of the schiff base complexes with DNA, the constant binding of the ligand to the DNA, and the number of binding sites (n) were investigated. The fixed binding values ​​(kb) and (kf) obtained from ultraviolet-light spectroscopy studies and fluorescence spectroscopy for Chromine derivatives are larger than the Barmox derivative, which suggests further interactions between the chlorine complex and DNA. The antimicrobial activity of the Schiff base Vanadil Complex, on the gram-positive bacteria of Staphylococcus aureus and the worm-negative bacteria of Escherichia coli, was studied and compared with the standard antibacterial materials. Based on the results, both schiff base vanadium complexes of the study are approximately equal to the amount of good antibacterial activity, with the difference that the derivative contains a functional group of chlorine has more antibacterial activity than the derivative containing the bromine functional group against the bacteria Is negative. From these observations, it can be concluded that the antibacterial activity of these complexes is related to the presence of Cl and Br substituents.

In this study, Polyethersulfon/Diatomaceous composite membranes were prepared by Phase Inversion method with different percent of diatomaceous particles as additive. The physical and chemical characterization of membrane, morphology and water contact angle were investigated by FT-IR, TGA, SEM and CA techniques. The effect of diatomaceous particles on water flux and Bovine Serum Albumin percentage removal were discussed. Difference in the pore structure and finger like cross section morphology with the presence of diatomaceous particles were observed in PES membranes. The results showed membrane performances such as hydrophilicity and water flux were enhanced by adding diatomaceous particles and modified membranes showed better antifouling properties.

Magnetite metals with mixed valence, have high physical, chemical, magnetic and transport properties due to the presence of synthetic Mn4+ and Mn3+ ions in their crystalline structure. In the present study, doped lanthanum manganite (La0.7Ca0.3MnO3) was prepared by hydrothermal method. The as prepared powder was calcined based on the results of the thermal gravimetric analysis characterization (TGA). The results of XRD and FTIR analyses indicate that the compound is composed of single-phase structure without impurity and nanorod morphology with a mean length of 126.8 nm. The La0.7Ca0.3MnO3 composition has a band gap of 1.83 eV that indicating its usability as a photocatalyst in the visible light region.
The Rhodamine B cationic (RhB) was used as a model of wastewater to study the photocatalytic activity of La0.7Ca0.3MnO3 composition under visible light irradiation. The results of the removal of RhB by the heterogeneous photocatalytic oxidation process show that, over a period of 90 minutes, more than 80% of rhodamine is eliminated, and the overall reaction rate is first order and is equivalent to 0.020 min-1.

Epoxy and dicyclopentadien (DCPD) are two common healing agents, which are introduced into epoxy matrix through encapsulation in order to prepare self-healing composites. In a comparative study, the compatibility of healing agents and epoxy matrix is investigated through experimental tests and DFT calculations. The interaction energy is considered to be the determinative parameter in DFT calculation. The values of total interaction energy are -0.14eV for DCPD and +0.169eV for epoxy absorbing on epoxy matrix. According to the obtained results from DFT, an attraction between DCPD and epoxy matrix is observed. DOS and charge analysis of these systems are fulfilled and demonstrated the charge transfer of 0.07 e from epoxy to DCPD. The obtained data reveal the most charge transfer is occurred in DCPD-epoxy, which affects the mechanical properties of healed composites. To examine the mechanical properties, tensile strength parameters are measured experimentally and demonstrated the improved ultimate strength of 783.49 MPa in DCPD/epoxy system rather than the ultimate strength of 571.87 MPa in epoxy/epoxy system. Also elongation at break in DCPD-epoxy system is improved to 3.44% compared to 1.84% in epoxy/ epoxy blend. These findings highlight the role of interaction energy in mechanical properties of polymeric interface, and prompt further experiments and simulations to confirm this effect.

Quantitative structure-activity relationship (QSAR) study on the piperidone-grafted mono- and bis-spirooxindole-hexahydropyrrolizines as potent butyrylcholinestrase (BuChE) inhibitors were carried out using statistical methods, molecular dynamics and molecular docking simulation. QSAR methodologies, including classification and regression tree (CART), multiple linear regression (MLR), principal component analysis (PCA) and principal component regression analysis (PCRA). Three descriptors in three classes: 3D-Morse, WHIM and GETAWAY descriptors were selected by SPSS software and then applied in the final tree structure to describe the inhibitory activities. Docking simulations were carried out using AutoDock Vina softwares for all inhibitors. Docking results showed that the studied BuChE inhibitors have two commons binding modes. Molecular dynamics results obtained by Gromacs showed that the more potent inhibitor has more interaction with the enzyme and higher effect on the enzyme structure.

Ion selective electrodes (ISE) based on sol–gel process usingtetraethoxysilane(TEOS), diethoxydimethylsilane(DEDMS) and oxalic acid as ionophore, was successfully developedfor detection of Pb2+in aqueous solution.The response of the electrode and also its characterization were estimated by different methods includingpotentiometry measurement, Fourier TransformInfrared (FTIR) and scanning electron microscopy (SEM). The results indicate that the electrode response depends onionophore concentration. In these ion selective electrodes, 0.5 wt.% oxalic acid gives the best sensitivity for Pb2+.The sol–gel electrodeshows linear response with Nernstian slope of 28.63 mV/decade toward lead ionover the concentration range 6.1×10–6 to 1.7×10–2. Also, the electrodes shown detection limits of 1.0×10−7 M. The response time of this electrode was obtained 15 sec. at linear dynamic range and lifetime of nearly 2 months.The electrodeis suitable for use in aqueous solutions in a wide pH range of 4–6.All the obtained results indicate that the proposed lead ion sensor electrode have good reproducibility, repeatability, stability, selectivity and a fast response time.

In this work, we develop a correlative model based on the surface tension data in order to calculate thermodynamic parameters, such as interaction energy between components (Uij), activity coefficients and etc. In the new approach, by using Li et al. (LWW) model, a three-parameter surface tension equation is derived for liquid mixtures. The surface tension data of 54 aqueous and 73 non-aqueous binary mixtures have been correlated as a function of composition using the new model, then the interaction energy between two compounds (Uij) of mixtures and their activity coefficients have been calculated with the results of this model. The average relative error obtained from the comparison of experimental and calculated surface tension values for 127 binary systems is less than 2.8%.In order to evaluate new method, the obtained values using this method were comparable with the results of the UNIFAC group contribution model.

Effect of charge on the structural properties of Wurtzite ZnO doped with interstitial hydrogen was investigated using Density Function Theory. Calculation performed using Quantum Espresso package with Generalized Gradient Approximation (GGA). Calculations for formation energy showed that H is more stable than H0 and H- doping in this structure. Charge density calculation and Bader analysis showed that for all three H, H0 and H- states hydrogen due to its higher electronegativity in compared with Zn atoms, joins to oxygen and increases its charge and repulses zinc atom. Hydrogen doping affects on volume of supercells due to locating in space charge density, therefore cell parameters and volume of supercell decrease in H state, while these values increase for H0 and H- states.

The concentration of ground-level ozone is the result of thousands of complex chemical reactions. Basically, an increase of ozone concentration occurs in the presence of NOx, VOCs, and the sun’s radiation. This study deals with analyzing the ground-level ozone in Isfahan city from November 22 to December 21 (a full solar month) in 2009. According to the observations made by the Isfahan Meteorological Organization, photochemical smog was visible over the city during this month. The data used in this study include NO2, NO and O3 concentrations and the meteorological variables of temperature, relative humidity and wind speed which have been measured in Isfahan in 2009. The analyses were carried out for the sunshine hours in two time periods of 9 to 12 am and 6 am to 15 pm whose main characteristics are:A) During 6–15 period: the sun rises from 6 am and by becoming closer to the dusk, i.e. about 15 pm, both the radiation intensity, and temperature decrease;
B) During 9–12 period: the higher temperature, radiation intensity, and traffic are the effective factors in the emission of pollutants when compared to the other hours of the day.
The days under study are classified based on maximum, minimum and average ozone concentration. In order to analyze the tropospheric ozone and smog creation, in this study, the photochemical and semi-empirical models were used. The kinetic and mechanism of a number of photochemical reactions effective in ozone formation were taken into account in order to analyze the changes in ozone concentration. Calculations were carried out by using the Excel and Matlab software programs. Making use of the steady-state approximation method and considering oxygen atom in the steady state, the reaction rates have been computed. The differential relation obtained (d[O3]/dt = k2k1[NO2]- k3[O3][NO]) is a function of three variables of NO, NO2 and O3 concentrations. The amounts of reaction rate (d[O3]/dt) and also the rate constants k2k1 and k3 were also calculated. Analysis of the experimental relation between the activation energy and the results obtained from calculations indicate that the reactions that take place in the troposphere can be considered rank 3 reactions. In the troposphere, the quantum of energy (hν), which is released in some reactions, is very strong. The activation energies obtained for all days of this study include negative values, and this confirms the fact that the energy of the photons of the sun is needed to change NO2 and O2 to O3 in the troposphere. Based on the negative activation energies obtained, we can consider the reaction NO2㭯 hν→NO as the mechanism for the tropospheric ozone production in Isfahan.
The creation of photochemical smog, SP(t) with t denoting the time, during the mentioned days was studied based on the Jonson’s semi-empirical model. The relations obtained based on the changes in NO and O3 concentrations with respect to time show that smog creation follows a quadratic nonlinear relation.
In general, the increase of the concentration of pollutants on the ground as a result of photolysis reactions has led to the production of ozone concentrations. The results achieved from the analysis of reaction rate, smog creation, and the resulting curves indicate that ozone concentration has not been uniformly increasing or decreasing during the studied days, but there were both the increasing and decreasing trends. In general, the photochemical reactions taken place in the atmosphere of Isfahan city have caused both production and loss of ozone. Consequently, the investigation showed that the changes of the ozone concentrations under the effects of the solar radiation followed the same pattern in autumn 2009. On the other hand, the changes in the ozone concentration on the ground level caused changes in smog creation during the studied time. With regard to the above-mentioned arguments and on the basis of the effect of nearly the same conditions, a constant process prevailed. It could be predicted that this pattern will be the same in the future years.

Gasoline with euro 5 standard and improvement of selectivity of isomer products to aaromatic products in gasoline is very important in oil refinery. In this paper، Pt-Re-Sn Al2O3 catalyst prepared with imperegnation procedur. Then، The activity and catalytic reactor tests for prepared catalysts and commercial catalyst with same of commercial catalytic reforming process conditions and industrial feed in differential plug flow reactor of catalysis and nano technology division، research institute of petroleum industry pilot plant were done. The composition of Pt and Re in catalyst prepared was 0. 22 and 0. 44 and range of Sn composition was 0. 06،0. 1، 0. 2 and 0. 3 weight percent. After activity test and analysis of products، selectivity of isoparaffins products to aromatics products was compared. The results show that the selectivity of isoparaffin to aromatic products at two different temperatures (490-510 °C) for prepared catalyst with 0. 3 weight percent of tin and commercial catalyst were 39. 5، 29. 7، 4. 4 and 13. 2، Respectively. Finally، comparison of selectivity of four prepared catalysts and commercial catalyst in two operation conditions show that prepared catalyst with 0. 3 weight percent of tin at 490°C is suitable for new catalytic reforming process.

In this study the use of nano structured γ-alumina as a new and convince adsorbent for removal of cadmium ions from aqueous solution was investigated. The equilibrium adsorption level was determined as a function of the solution pH, temperature, contact time, initial adsorbate concentration and adsorbent doses. Adsorption isotherms of Cd(II) on adsorbents were determined and correlated with common isotherm equations such as Langmuir, Freundlich and Tempkin models. The isotherm data fitted well to the Langmuir isotherm. The maximum adsorption capacity for Cd(II) on nano structured γ-alumina was 76.92 mg g-1. The adsorption kinetics was investigated and the best fit was achieved by a second-order equation. The thermodynamic parameters such as free energy (ΔG0), enthalpy (ΔH0) and entropy changes (ΔS0) for the adsorption of Cd(II) were computed to predict the nature of adsorption process.