Phytochemical composition and in vitro antimicrobial and antioxidant activities of some medicinal plants

Different parts of three plants (Primula auriculata, Fumaria vaillantii and Falcaria vulgaris) were extracted with three different solvents to yield 72 crude extracts. The phytochemical analysis (chemical screening, GC–MS) of three plants was investigated for their antioxidant and antibacterial activity using nine Gram-positive and Gram-negative bacteria. The principal antioxidant and antimicrobial components were determined using HPLC with UV detection. All extracts possessed antibacterial activity especially methanolic extracts from flowers of P. auriculata. The DPPH-radical scavenging assay exhibited high antioxidant activities in three plants (more than 80% at 50 μg). The F. vulgaris showed high content of carvacrol (29.8%) as main component. The contents of carvacrol and fumaric acid in the methanolic–water extracts were 1119 and 1966 mg/l respectively. Our results indicate that these plants would be able to promise sources of natural products with potential antibacterial and antioxidant activity.     

Modification and Characterization of Hemp and Sisal Fibers

This work is to investigate the effectiveness of the surface treatment technique of fiber impregnation in polymer solution in improving compatibility of natural fibers with matrix. Hemp and sisal fibers were treated through polymer coating in comparison to acetylation, alkalization/acetylation, and silanization. Different analytical techniques were employed to examine effect of surface treatment, including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) in nitrogen and air. FTIR showed acetylation combined with alkalization led to the highest hemicellulose and lignin removal among all treated fibers for both fibers, while polymer coating led to an increase at peak around 1,736 cm^?1 due to the carbonyl group. SEM micrographs of treated fibers showed cleaner surfaces due to removal of waxy substances and lignin during treatments. Thermal stability of treated fibers increased based on TGA results except for the alkalized/acetylated fiber. Acetylated fibers had the lowest moisture content, thus demonstrating that acetylation is an effective technique to reduce the hydrophilic tendency of natural fibers. In comparison, polymer coating was not as effective as other treatment methods.     

Particle Swarm Optimization for Automatic Calibration of Large Scale Water Quality Model (CE-QUAL-W2): Application to Karkheh Reservoir,Iran

An automatic calibration of water quality model is developed in this research. Automatic calibration as the process to determine the parameters appearing in the equations of a 2-dimensional, hydrodynamic, and water quality models (CE-QUAL-W2) is carried out with Particle Swarm technique as an optimization tool. In the calibration of the CE-QUAl-W2 model, evaporation as a significant parameter influences the thermal profile and water surface elevation in reservoir, simultaneously. Therefore to consider the simultaneous effects of the water temperature variations on water surface elevation in the reservoir, a multi objective technique is used to minimize the weighted sum of total deviations of temperature from field data at check points on monitoring days and those of water surface elevation on daily monitoring period. The proposed approach overcomes the high computational efforts required if a conventional calibration search technique was used, while retaining the quality of the final calibration results. The automatic calibration approach is applied in temperature and water budget calibration of Karkheh reservoir in Iran. Applying the proposed automatic calibration approach, shows the produced results by the CE-QUAL-W2 model with the calibrated coefficients agree closely with a set of field data.