PLANT LEAF ASSISTED SYNTHESIS AND APPLICATION EVALUATION OF SILVER NANOPARTICLES

Abstract- Use of the plant material for the bioreduction of the metal for the nanoparticles synthesis is currently the choice of methods in bionanotechnology. In the present study, silver nanoparticles (AgNPs) were rapidly synthesized usingan aqueous extract of Ocimum sanctum (Tulsi) and Partheniumhysterophorous(Congress grass). The synthesis process was standardizedbased on the trials. The process of AgNPs formation usingwith Tulsi aqueous extract was carried out with 0.1 mMAgNO3solution and referred as a T1 sample,whereas 2.0 mMAgNO3was used with the Congress grass aqueous extract as a C4 sample.These AgNPs were characterized by means of UV-Vis spectroscopy, scanning electron microscopy(SEM), electron diffraction spectroscopy (EDX) and Dynamic light scattering (DLS).AgNPsformation was confirmed by Surface Plasmon Resonance as determined by UV–Visible spectra analysis in the range of 250 to 750 nm. Maximum absorbance (λ max) peak was reported between 406 to 446 nm in T1 and C4 samplesfollowed by SEM characterization showed a uniform distribution of nanoparticles, with an average size of 68.74 nm and 108.6 nm in T1 and C4 samples respectively. Average size measurement was confirmed by DLS and the presence of silver was confirmed by EDX.Application including mice spleenocytes viability, bactericidal effects, Synergistic effect with Antibiotic and pesticides adsorption suggest the wide scope AgNPs in various fields

Accumulation of Heavy Metals by Some Aquatic Macrophytes in Estuarine Zone of River Tapi

Abstract: Aquatic plants are known to accumulate metals from their environment. The study focuses on assessment of heavy metal accumulation in certain aquatic macrophytesin comparison with water and sediments for phytoremediation. The aim of this study is to measure the concentrations of Cd, Co, Cu, Pb and Zn in four different species of aquatic macrophytes collected from estuarine zone of Tapi river near Surat city of Gujarat. Plants along with surface sediments and water were analyzed for Cd, Co, Cu, Pb and Zn contamination. The plant species selected were : Eichornia cressipes (Mart.)Solms-Loub (root and shoot) Persicaria glabra (Willd.)M.Gomez (root, stem and leaf) Pistia stratiotes L. (root and shoot) and Ceretophyllum demersum L. (whole plant). Samples were analyzed for heavy metals by AAS (Atomic Absorption Spectrophotometer). The greater accumulation of heavy metals was observed in the shoot of Pistia stratiotes. The lowest content was observed in Ceretophyllum demersum. Based on the concentration observed in the river's vegetation, the five heavy metals arranged in the descending order are : Pb > Cu > Zn > Co > Cd. The results of concentration of heavy metals in selected plants were compared with the standard, normal and critical toxicity range in plants. The detected value of Cd falls within normal range, while that of Co, Cu, Pb and Zn were within the critical range. However, Co and Cu showed the highest accumulation with alarming toxicity levels, which areconsidered as one of the most hazardous pollutants in river. Species like Persicaria glabra and Pistia stratiotes are also proposed as bioremediants, which are the most useful plant species in phytoremediation studies due to their ability to accumulate heavy metals in high concentration and their availability throughout the year

MODELLING OF PMSM AND FOC OF PMSM BASED ON SPWM WITH MATLAB/SIMULINK

ABSTARCT: Permanent-magnet-synchronous-machine (PMSM) drives have been increasingly applied in a variety of industrial applications which require fast dynamic response and accurate control over wide speed ranges. Permanent magnet (PM) synchronous motors are widely used in low and mid power applications such as computer peripheral equipments, robotics, adjustable speed drives and electric vehicles. The mathematical model of PMSM is analyzed and the system model of FOC vector control has been established. The control system has been also simulated by MATLAB/Simulink