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ThesisItem Open Access Study of electrical and magnetic properties of cobalt based metallic glasses and composite material(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2005-07) Agrawal, Rati; Kushwaha, R.P.S.There are many materials of commercial importance; composite materials and metallic glasses are two such important materials among them. Wide variety of technological and industrial applications of these materials motivates the present work. Cobalt based metallic glass of nominal composition Co60B12Si12Fe4Mo2Ni1 and cobalt based composite material prepared by varying concentration of cobalt metal powder in plaster of paris was used for investigating their electrical and magnetic properties. For cobalt based composite material change in A.C. magnetic susceptibility with both frequency and concentration have been taken into account. Similarly temperature and concentration dependence of electrical resistivity of composite material was investigated. From experimental results obtained, A.C. magnetic susceptibility was found to decrease with frequency for all concentrations and increase in susceptibility was observed when plotted with concentration. when electrical resistivity of cobalt based composite material was investigate for its temperature dependence, slight decrease in resistivity or a dip was observed for all the concentrations i.e. for all the samples with different concentrations of cobalt metal powder in plaster of paris. Energy losses in the samples were also measured by studying their hysteresis loops for two different frequencies.ThesisItem Open Access Study of the role of pair transfer processes on isotope effect in superconducting TTF[Ni(dmit)2]2 systems(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2004-06) Pant, Manju; AjayIn the present investigation, we have studied the role of interband pair transfer processes on isotope effect in layered TTF[Ni(dmit)2]2 systems. For this purpose we have considered two chain Hubbard model that includes the intra and intermolecular vibrations in the presence of electron Coulomb energy and the electron transfer energy between the chains. Such a model calculations will be applicable for the organic superconductors where molecular layered structures are available. We obtained the expressions for the superconducting order parameter, transition temperature and finally the isotope effect coefficient ( ) using double time Greens’s function equations of motion technique within BCS mean field approximation. Finally the numerical analysis show that isotope effect coefficient ( ) depends on the intra and interlayer molecular vibrations, the pair transfer processes and also on the superconducting transition temperature (Tc) in layered organic superconductors like TTF[Ni(dmit)2]2 . On the basis of our model calculations we have predicted the effects of the pair transfer processes, the density of states at Fermi level and the chemical pressure on the isotope effect coefficient which need to be tested through rigorous experimental investigations on these systems.ThesisItem Open Access Determination of leaf water parameters of sarpgandha (Rauwolfia serpentina L.) plant using beta gauging technique(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2013-07) Tiwari, Bhoopendra Chandra; Joshi, G.C.The present study is concerned with the determination of the physiological parameters such as fresh leaf thickness and water content (actual and relative) of a medicinal herb Sarpgandha (Rauwolfia serpentina L.) leaves. We have measured the changes in these physiological parameters as a function of height of leaves from ground level. These parameters were calculated by beta gauging method by using 204Tl and 90Sr- 90Y beta sources of energy 0.77 MeV and 2.28 MeV respectively. The results were also compared with weighing method. The observations showed that the fresh leaf thickness decreased exponentially with the height of plant leaves from ground level. However, the actual water content and relative water content increased exponentially with the distance of leaves from ground level. The actual water content and the relative water content showed the linear relationship. The mass absorption coefficient ( ) was also determined by the beta gauging method and compared with the empirical relation. The observations showed that the mass absorption coefficient depend only on the end point energy of beta particle. The study further suggests that the beta gauging method is a rapid, effective, non-destructive and powerful tool to follow the changes in physiological parameters of plant leaves.ThesisItem Open Access Size and shape dependent thermodynamic study of nanometals(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2017-07) Uniyal, Shalini; Joshi, Deepika P.Thermodynamics of nanometals has became a great area of research due to their wide range of applications in many field of science. In the present work four different models i.e. Qi’s model, Qi-Wang’s model, Jiang’s model and Lu’s model have been used to study size and shape dependent melting temperature, Debye temperature and specific heat of Nanometals. These thermodynamic properties are calculated for different sizes and shapes like spherical, regular tetrahedral, regular hexahedral and regular octahedral. Sn, Pb, Bi, In, Cd, Al, Au, and Ag nanometals are taken for the study of size and shape dependent melting temperature, the size and shape dependent study of Debye temperature is done for Au, Fe, Sn and Co nanometals. Ag and Au nanometals are used for the study of specific heat. The calculated results obtained from these models are compared graphically with available experimental and simulated data.For melting temperature, the results obtained from the equation given by Qi-Wang’s model (for D<15nm) and Qi’s model ( for D>15nm) are found closest to available experimental and simulated data. Jiang’s model is found to be most suitable for the study of Debye temperature of nanometals. For the study of size and shape dependent specific heat, modified specific heat relation of Qi’s model gives better result. Present study reveals that the thermodynamic properties of nanometals are not only size dependent but also varies with shape for small sized nanoparticles. The shape of nanometals for particular size can also be predicted with the help of this study. The shape factor is found to be more pronounced at lower sizes while its effect becomes negligible for higher sizes.ThesisItem Open Access Calculation of (p,n) & (n,p) reaction cross-sections based on TALYS-1.6 for the production of medical radioisotopes(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2017-07) Dasila, Raj Kumar Singh; Joshi, G.C.The cross-section (excitation functions) of neutron and proton threshold reactions has gained considerable importance for the production of Therapeutic radioisotopes in the present era. The present study based on TALYS 1.6 code to calculate the cross section theoretically. This code has been used to evaluate (n,p) & (p,n)reaction crosssections for the production of therapeutic radioisotopes (64Cu, 64Ni, 67Cu, 89Sr, 90Y, 124I, 125I, 153Sm, 169Y, 186Re, 192Ir) for which a very few experimental data are available in EXFOR but some are discrepant. These theoretical calculations have been performed within the frame work of the level density parameter with pre-equilibrium effects using recent TALYS 1.6 code from the energy range threshold to 20 MeV. Before running the code optimization of input parameter (level density formulation) has also been done. The obtained results have been compared with EXFOR data and various available data files (ENDF, IAEA and TENDL) along with the experimental data available in the literature. It is concluded that computed results using TALYS 1.6 code is compatible with the experimental data from the literature.ThesisItem Open Access Effect of size dependent bulk modules on compression of nanomaterials(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2017-07) Belwal, Deeksha; Joshi, Deepika P.High pressure study is very important for better understanding of matter in the world around us and to create entirely new form of matter. In the present thesis, a theoretical study of the effect of size dependent bulk modulus on compression of nanomaterial has been done. Murnaghan, Birch-Murnaghan, Usual tait and Shanker equations of state are modified to include the effect of size on compression of nanomaterials. Then the applicability of these modified equations has been checked for Al2O3 (37 nm and 67 nm), Ge (13 nm and 49 nm), SnO2 (3 nm, 8 nm and14 nm), Ni (20 nm and 29 nm), PbS (2.6 nm, 5.4 nm and 8.8 nm) nanomaterials. These four equations are modified by considering linear and non-linear relation between size of nanomaterial and bulk modulus respectively, to investigate compresional behaviour of above nanomaterials. In both cases the results are compared with available experimental data. Present study reveals that modified equations which include linear relation between bulk modulus and size of nanoparticle are not valid for all chosen nanomaterials, while modified equations which include the non-linear relation between bulk modulus and size of nanoparticle are in good agreement with experimental data for all above nanomaterials. Shanker equation gives slightly different results from experimental results at high pressure. It is concluded that the general relation between bulk modulus and size of nanoparticle is not linear. Value of non-linearity parameter ϵ can be useful to understand behaviour of small particles. The non-linear size dependent modified equations of Murnaghan, Birch-Murnaghan, Usual Tait and Shanker may be helpful for compressional study nanomaterials.ThesisItem Open Access Study of quantum error correction and fault tolerant quantum computing(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2017-07) Mehta, Saurabh; Johri, U.C.ThesisItem Open Access Multi-elemental analysis of two varieties of tulsi using EDXRF and AAS(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2017-07) Bhandari, Deepak Singh; Joshi, G.C.Nowadays many medicinal plants are isolated and analysed for their medicinal properties and healing components by the researchers. Tulsi and its varieties (Rama and Shyama Tulsi) are a very important plant in the traditional medicinal system. The aim of this work was to analyse elemental content in different parts viz. leaves, stem, and roots of two varieties of Tulsi. Energy Dispersive X-Ray Florescence (EDXRF) technique was used to analyse samples of different parts of Tulsi. Ten elements viz. Mg, P, S, Cl, K, Ca, Mn, Fe, Cu, and Zn were identified and their concentrations were determined. We have also used Atomic Absorption Spectroscopy (AAS) to determine the concentration of four elements Mn, Fe, Cu, and Zn in various plant samples and found almost similar results as by EDXRF technique. Both varieties of Tulsi were found to be rich in the elemental content in the leaves and roots. Translocation of various elements in different parts of the plants and their biological importance for human body were discussed in brief. A comparative study of elements in leaves, stem, and roots between two varieties of Tulsi was established, and it was observed that Rama Tulsi was found richer in elemental content than Shyama Tulsi. No toxic element was detected in the both varieties of Tulsi which proves that it suitable for the medicinal use. This plant attracts a special attraction as a source of iron, especially for humans with low iron intake and for the people with low level of haemoglobin. The results of the present study provide justification for the use of Tulsi and its varieties in the treatment of several diseases since they contain a wide range of macro and micro elements in all its parts which are vital to human health. This analysis may be useful in the exploration of the medicinal importance of these two varieties of Tulsi.ThesisItem Open Access Study for the effect of size on compression for different shape of nanomaterials(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2017-07) Tamta, Pramesh; Munish Kumar