http://nopr.niscair.res.in/handle/123456789/2269 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/2460 Title: Effect of 50 MeV Li-ion irradiation on thermal and structural characteristics of polymer blends <br/> <br/>Authors: Sharma, Anita; Qureshi, Anjum; Singh, N L; Shrinet, V; Avasthi, D K; Rakshit, A K <br/> <br/>Abstract: Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA) investigations of pristine and irradiated blended films were carried out. The experimental observations provide a quantitative evaluation of the IR results on the deterioration of chemical bonding with irradiation fluence. It is found that chemical structure is subjected to alteration in intensity with the fluence. It is revealed from TGA thermogram that blended polymer consisting of PVC and EVA in equal composition exhibits better thermal properties. DSC thermograms indicate that Tℊ has been shifted to lower temperature with broadening of peak, while no change in Tm has been observed up to the fluence of 10¹⁴ ions/cm². <br/> <br/>Page(s): 127-130 http://nopr.niscair.res.in/handle/123456789/2303 Title: Effect of three-body interaction in strongly interacting Bose-Einstein condensate in isotropic and highly anisotropic magnetic trap <br/> <br/>Authors: Tewari, Shri Prakash; Silotia, Poonam; Saxena, Aditya; Gupta, Lokesh Kumar <br/> <br/>Abstract: Ground state properties of Bose-Einstein condensate of 20000 ²³Na atoms confined in isotropic and highly anisotropic magnetic traps in the presence of three-body interaction, in addition to the two-body and hard-core interactions, have been theoretically studied by solving modified highly non-linear Gross-Pitaevskii-Ginzburg (GPG) equation. There is increasingly significant change in the chemical potential, total and differential energies per particle as the aspect ratio, λ, is increased from 0.1 to 1.0, with respect to the corresponding values when only two-body and hard-core interactions are considered. The condensate order parameter changes drastically and becomes quasi 1-dimensional, as λ is varied from 1 to 0.1. <br/> <br/>Page(s): 173-179 http://nopr.niscair.res.in/handle/123456789/2302 Title: NMR spin-lattice relaxation time and activation energy in some molecular systems <br/> <br/>Authors: Singh, Ajay Kumar; Mehrotra, N K <br/> <br/>Abstract: The experimental values of NMR spin-lattice relaxation time (T₁) of N-butylamine, di-isopropylamine, N, N, N- tributylamine, N, N- dimethylformamide, N, N- dimethylacetamide have been reported. The experimental values of T₁ have been correlated with the calculated values of T₁ obtained using various equations of the dielectric relaxation time (). It has been concluded that Murty’s equation is a better representations of the dielectric relaxation phenomenon. The values of activation energy (ΔEA) obtained using dielectric relaxation time have been correlated with calculated values obtained using Arrhenius equation of NMR spin-lattice relaxation time (T₁) for these compounds. <br/> <br/>Page(s): 168-172 http://nopr.niscair.res.in/handle/123456789/2301 Title: Dielectric relaxation study of binary mixtures of ethyl alcohol and N, N-dimethylformamide in benzene solution from microwave absorption data <br/> <br/>Authors: Sharma, Vimal; Thakur, Nagesh; Sharma, Dhani Ram; Negi, Nainjeet Singh; Rangra, Vir Singh <br/> <br/>Abstract: Dielectric constant (Ɛ′) and dielectric loss (Ɛ″) of ethanol (C₂H₅OH) and binary mixtures of ethanol and N, N-dimethylformamide (DMF) in benzene solutions have been measured at microwave frequency 9.883 GHz at different temperatures 25, 30, 35 and 40ºC. Standing microwave techniques and Gopala Krishna’s [Trans Faraday Soc, 33 (1957)767.] single frequency concentration variation method have been used for above measurements. The measured values of Ɛ′ and Ɛ″ have been used to evaluate dipole moment (μ) and relaxation time (). Various thermodynamic parameters (ΔH ΔFand ΔS) for the dielectric relaxation process of binary mixtures containing 50% mole fraction of OH have been calculated using Eyring’s rate equations. Comparison has been made with the corresponding energy parameters for viscous flow process. It is found that the dielectric relaxation process can be treated as the rate process like the viscous flow process. Non-linear variation of relaxation time with molar concentration of ethanol in the whole concentration range of the binary mixture indicates the existence of solute-solute type of molecular association. <br/> <br/>Page(s): 163-167