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2017 - 20182
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Author: Arya, Meenakshi × End date: 2019 × Start date: 2013 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Phytoremediation of soil polluted with heavy metals using tomato and spinach
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-05) Arya, Meenakshi; Singh, Vir
    The present study determines heavy metals (Cu, Pb and Zn) accumulation in different parts of tomato and spinach along with the adverse effects of these heavy metals on the physic- chemical characteristics of soil. Tomato and spinach are well known hyperaccumulators. It was observed that the presence of heavy metals in the soil decreases the soil organic contents. The pH of soil was significantly (p<0.05) higher in normal soil and lower in the contaminated soil. Along with the pH soil respiration was also significantly (p<0.05) reduced in contaminated soil, whereas there was no significant difference (p>0.05) in soil dehydrogenase activities. Nitrogen, phosphorus and potassium were found significantly low (p<0.05) in the contaminated soil than in the normal soil. However, there was no significant variation in the organic carbon content of both the soils. When we examined the concentration of heavy metals in the shoots of both plants, with the help of Atomic Absorption Spectrophotometer, the concentration of Cu and Pb was found high in the shoots of contaminated tomato and low in the shoots of tomato when grown with spinach in the same control soil pot. But Zn did not vary significantly (p>0.05) in all the treatments. In roots of these plants, Cu and Pb was recorded maximum in the roots of treated spinach and Zn was accumulated in higher amounts by the roots of treated tomato.
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    ThesisItemOpen Access
    Nonisothermal kinetics and thermodynamics of solid-state decomposition of polyacrylamide/ferrite nanocomposites
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2017-08) Arya, Meenakshi; Zaidi, M.G.H.
    The present research work deals with investigation of nonisothermal kinetics and thermodynamics of solid state decomposition of selected polyacrylamide derivatives and their polymer nanocomposites (PNCs).The PNCs investigated for this purpose were those containing ferrite nanoparticle (FNPs) with two different sizes (nm) viz; 10.5 and 21.5.Thermal characteristics of FNPs, homopolymers and respective PNCs was investigated through simultaneous thermogravimetric-differential thermal analysis-differential thermogravimetry (TG-DTA-DTG) in air. Data obtained from TGA were used to investigate kinetics of thermal decomposition process by applying Coats –Redfern (CR) and Horowitz Metzger (HM) methods. TG data reveals that the thermal stability of FNPs was regulated with size. In general, FNP-I with small size (10.50 nm) was more stable over FNP-II (21.15 nm). PNIPAM has shown highest thermal stability, followed by PDMAEMA and PAEMA. In general, HM methods have shown higher values of activation energy over CR method. Both the methods have provided a wide difference for Ea and A but identical results for entropy change and enthalpy change for most of the thermal degradation processes.