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ThesisItem Open Access Study for the equation of state of nanomaterials(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-11) Prachi; Munish KumarInterest in nanomaterials grew a lot among researchers due to its numerous applications at high pressure in this world. Nanomaterials show various properties because of their small size in the order of nanometers. Their applications are in areas of sensors, drug delivery, medical diagnostics, gene therapy, and catalyst. Nanotechnology developed due to such applications. We developed a simple method to study the effect of pressure, size and shape on nanomaterials. We studied the pressure dependence of V/V0 for various shapes and sizes. The materials which we used are WC (25nm), MgO (20nm), Re0.52W0.48B2 (30nm), Ho2O3 (14nm), α-Ga2O3 (14nm), β-Ga2O3 (14nm), ReB2 (40nm), and ZnO2 (3.1nm). This is due to the availability of experimental data of compression corresponding to them. We analyzed them in various shapes and sizes at room temperature. We also found that shift in the isotherm curve was large for film shape and small for the tetrahedral shape of nanomaterial. We concluded that film-shaped nanomaterials are most compressible whereas tetrahedral-shaped nanomaterials are least compressible due to differences in surface to volume atomic ratio for different types of shapes. The results are in good agreement with available experimental data which proves the validity of the formulation developed in the present work. Simplicity and applicability is an important part of the present thesis.ThesisItem Open Access Preliminary studies on methylene blue dye removal by coconut shell coke(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-10) Saxena, Abhishek; Goel, PujaThe unprecedent demand of organic and inorganic dye molecules in food and packaging, fabric, paper and plastic industries etc. have produced undesired hazardous products leading to severe contamination of the water resources. These molecules are generally very stable and don’t easily degrade therefore the remediation of contaminated water from such industrial waste is a big issue. In this context, coconut shell derived charcoal (CC) is prepared in our lab as an adsorbent material for methylene blue dye (MBD) adsorption owing to its availability in our region at a very nominal cost. The experiments were performed in batches to evaluate the dye removal efficiency from aqueous solution by varying (i) MB concentrations and (ii) adsorbent dosages. UV–Vis spectroscopic studies have been used to estimate the dye removal efficiency. A dye removal efficiency as high as 98.80% was achieved with adsorbate concentration 20 mg L-1 using 0.01 gm of CC adsorbent whereas under same parameters AC gives 98.67% efficiency. Maximum efficiency was found to be 99.14% with 0.10 gm of CC. These studies revealed the effectiveness of CC over AC for MBD removal. The local small industries can easily adopt this technology at a very nominal investment and can help in saving water resources as well as our environment.ThesisItem Open Access Artificial Neural Network (ANN) modelling of elemental concentration in soil using XRay Fluorescence (XRF) counts data(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-11) Rautela, Harshita; Singh, VirendraGenerally, fundamental parameter approach is used for the analysis of the XRF data for which various parameters needs to be calculated. To make the process less strenuous, Artificial Neural Network (ANN) has been used in the current work. The aim of the study is to develop a model of elemental concentration, after obtaining the Energy Dispersive X-Ray Fluorescence (EDXRF) intensities and counts data of soil samples. An ANN model is designed to obtain the concentrations of elements without using fundamental parameters. The designed network was the feed-forward neural network having two hidden layers with five and seven neurons in each layer, respectively. Quick propagation algorithm has been applied to the network. The network has been trained using supervised learning. A total number of 12 elements in soil samples, namely Mg, Al, Si, K, Ca, V, Mn, Fe, Cu, Rb, Sr and Pb, has been used for the training of the model. A wide range of concentration (7.66 ppm for Cu to 228360 ppm for Si), obtained using EDXRF results, were modelled by ANN. The correlation coefficient and R-square values for the training set came out to be greater than or equals to 0.97 for most of the elements. The R-square values for the prediction set were also satisfactory. Overall, good results were obtained by the ANN model for almost entire range of concentration except for a few elements. So, it can be concluded that ANN works well for the elemental concentration modelling avoiding the rigorous fundamental parameters approach. Multiple regression has also been applied and the results were satisfactory.ThesisItem Open Access Study of structural and optical properties of Cobalt Ferrite nanoparticles(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-10) Ritu; Srivastava, R.C.The cobalt ferrite nanoparticles are useful in many fields because of their admirable mechanical and chemical stability, highly magnetocrystalline anisotropy, moderate saturation magnetization, low eddy current losses and high coercivity. The present investigation was aimed to study the structural and optical properties of cobalt ferrite nanoparticles before and after the gamma irradiation with total dose of 500Gy and 1kGy. The cobalt ferrite nanoparticles were synthesized via sol-gel auto combustion method. The structural parameters were obtained through XRD pattern by using the OriginPro software and also by Rietveld refinement technique using FullProf software. The lattice parameter obtained were in the range from 8.403 Å to 8.360 Å. It decreased with increasing the total dose. The interplanar spacing decreased from 2.53 Å to 2.52 Å and specific surface area also decreased from 27.9m2/g to 21.3m2/g with the gamma irradiation. The X-ray density increased from 5.254g/cm3 to 5.336g/cm3 after irradiation. The crystallite size changed from 41nm to 53nm when calculated by Debye-Scherrer’s formula and from 47.63nm to 59.74nm when evaluated by W-H plot, with increasing the gamma dose. The tensile strain in the crystal changed to the compressive strain after the irradiation. The bond length, occupancy and the cation distribution were also changed by gamma irradiation. The optical analysis of cobalt ferrite was carried out by using the UV-Vis diffuse reflectance spectroscopy. The optical band gap was decreased with the gamma dose from 1.370 to 1.343eV. The value of energy band gap showed that the all samples were semiconductor in nature.ThesisItem Open Access Application of magnetic biochar in removal of Cadmium and Lead heavy metals from their aqueous solutions(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-11) Pant, Nidhi; Singh, VirendraHeavy metals toxicity in water is a major risk to public health and environment. Discharge of heavy metals originates from anthropogenic activities and once these metals enter in the water, it becomes polluted and unsuitable for drinking purpose. Lead and Cadmium are such two heavy metals which pose a serious threat to the human health. In the current research, adsorption method is proposed to remove the mentioned heavy metals from water using magnetic biochar. Various ratios of biochar and magnetite were mixed with TES in distilled water in an incubator shaker to prepare magnetic bio-composite. Various characterization techniques viz. FTIR, XRD and AAS were employed to study the physical and chemical properties of the composite and synthetic solutions of Pb and Cd. XRD analysis has confirmed the synthesis of magnetite nanoparticles. Presence of hydroxyl, carboxylate and alkane functional groups in the FTIR spectra of biochar gave an evidence for its hydrophilic nature and availability of anchoring sites for the NPs. Fe-O stretching and FeOOH stretching vibrations in case of magnetic biochar suggested the attachment of magnetite on biochar. The successful attachment of TES on magnetic biochar was confirmed by the presence of Si-O-C bond and Si-O-Fe stretching. The significant shift and decreased intensity of –NH2 group in FTIR spectrum of metal loaded magnetic biocomposite was a sign of complexation of metal ion with amine functional group. In batch experiment, adsorption characteristics of both Pb(II) and Cd(II) were investigated. It has been observed that magnetic biochar (MBC) shows very good adsorption behaviour at basic pH as maximum 99% heavy metal removal was observed and the process of heavy metal removal was instantaneous and efficient. Pseudo second order equation was best fitted kinetic model. The adsorption isotherm was better fitted by the Langmuir equation. The combination of various attractive properties like simple magnetic separation, lowcost, environmental friendly nature and good adsorption performance enable MBC application in lead and cadmium metals removal from drinking water.ThesisItem Open Access Size and pressure dependent thermophysical properties of nanomaterials(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-11) Pandey, Mahesh Chandra; Joshi, Deepika P.Present thesis is an effort to develop equations of state for the study of size and pressure dependent thermophysical properties of nanomaterials; such as bulk modulus, relative volume compression, melting temperature and Debye temperature .The proposed modified equations have been applied to study the thermophysical properties of Al (37nm), Bi (50 nm), Pb (6.7 nm), Cu (20 nm), In (20 nm), Ag (20 nm), Au (20 nm), Ni (20 nm), Sn (20 nm) nanometals. Study shows that the bulk modulus (B) of nanomaterials decreases with decreasing size but increases with increasing pressure. In the light of bulk modulus relative volume compression has been obtained. The relative volume change (V/V0) decreases with increasing pressure. The melting temperature is obtained with the help of Grüneisen parameter. The Grüneisen parameter shows decrement with the size decrement of nanoparticles, hence the melting temperature decreases with decreasing size. Present study reveals that the melting temperature shows superheating phenomenon under pressure and the similar increasing trend is shown by the Debye temperature as well. The obtained results show a very close agreement with the available experimental data, which supports the validity of the present work. So, the proposed equations of states can be helpful to study the thermophysical properties of nanomaterials under pressure.ThesisItem Open Access Optical study of rare earth doped nickel ferrite thin films irradiated with 100 MeV oxygen beam(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-10) Pant, Chitresh Mohan; Dixit, GaganFerrites are magnetic materials having spinel structure. They are important because of their various properties which make them applicable in many fields such asmedical diagnosis, electronic industry, automobile, military applications, etc. Properties of ferrites depend upon the synthesis method, temperature, cation distribution, doping with different metal ions etc. Swift Heavy Ion Irradiation is very unique tool to modify the properties of material. Present work is an attempt to study the effect of 100 MeV oxygen ion induced modification on structural and optical properties of 4% Ce and Gd doped Nickel ferrite thin films. The samples were synthesized by chemical route using citric acid and thin films have been prepared by Pulsed Laser Deposition technique. Structural and optical properties were studied using XRD and UV-Vis Spectroscopy. XRD confirmed the cubic spinel structure of pristine and irradiated samples. After doping with rare earth ions crystallite size was decreased and lattice parameter was increased. After irradiation at lower fluence , pure and Ce doped nickel ferrite thin films show some impurity which disappears at higher fluence while Gd doped films remain in pure phase. The reflectance spectra for all the samples were recorded by UV-Vis spectroscopy. The direct band gap was found to increases with doping of rare earth ion. For nickel ferrite thin films, band gap was found to increase with fluence of irradiation while for rare earth doped nickel ferrite thin films, there was not significant change in band gap. Both structural and optical studies indicate that Gd doping has enhanced the resistivity of nickel ferrite thin films towards irradiation induced changes in comparison to Ce doping. Swift heavy ion irradiation can be considered as an effective tool for modifying optical properties in comparison to doping with rare earth ions.ThesisItem Open Access Theoretical analysis of structural and magnetic behavior of Ce doped nickel ferrite nanoparticles(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-10) Fulara, Rajneesh; Dixit, GaganFerrites are magnetic materials having spinel structure. They are important because of their magnetic properties which make them applicable in various fields. Properties of ferrites depend upon the synthesis method, temperature, cation distribution, doping with different metal ions etc. In the present work, theoretical analysis of various structural and magnetic properties of Ce doped nickel ferrite nanoparticles NiCeyFe2-yO4 (Ce concentration y =0.01 to 0.08) has been done. Experimental data of X-Ray Diffraction, Mössbauer Spectroscopy and VSM has been taken from literature for structural analysis, cation distribution and saturation magnetization respectively. Ce ions being larger in size are assumed to occupy the octahedral sites. Different structural parameters like bond lengths, bond angles, site radii etc. were calculated assuming that all Ce ions are entering into the spinel lattice with increasing concentration. The calculated values show matching with experimental values only up to the 0.01 concentration of Ce. So it was concluded that Ce ions are not entering into the spinel lattice after the concentration of 0.01 but are moving toward grain boundaries. The cation distribution was again refined and structural and magnetic parameters were calculated which now show almost similar trend as the experimental values for all samples. Both theoretically and experimentally it was found that doping with Ce reduces the magnetization of nickel ferrite however there is difference between the calculated and experimentally observed values. Inclusion of some additional factors such as magnetic moment due to orbital motion and spin canting may give the possibility of getting same calculated values. This opens a scope for further experimental study of Ce doped ferrite samples.ThesisItem Open Access Tamarind wood derived soft coke for effective removal of methylene blue dye(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-06) Mohit Kumar; Goel, PujaColours play an important role in our life. Colour is a source of pleasure for everybody. Dyeing substances are used to impart colour on textile, plastic, leather, cosmetics, rubber, paper or any other material which we use in our daily life. Natural dyes were used till mid19th century. After that scientists started to developed dyes from chemicals. Synthetic dyes were cost-effective and easy to apply. Nowadays every product we use has been dyed with synthetic dyes. The problem withsynthetic dyes is that most of the dyes are toxic.Dyeing is always been a water-intensive process. So, industries are generating a large amount of contaminated water. This water is later released into waterbodies and has a bad impact on the aesthetic nature of the environment. In this research, a dye removal named adsorption is discussed. Adsorption is a popular method for waste water treatment and activated carbon is a very good adsorbent for this process. Forlarger industrial applications, AC is expensive. In current thesis, Tamarind wood derived Soft Coke was used as an adsorbent to compare the efficiency with commercially available activated carbon. Total 6 sets of samples of 2,5,10 & 20 ppm concentration (volume 10ml), MB were prepared. In the first four of them, CP was used as an adsorbent and for the remaining two samples AC with variable amount was used. After 3 hours of adding the adsorbent solutions were filtered with Whatman Filter Paper No. 1. The UV-Visible data of all filtered samples were recorded. With the help of the absorbance value of all the samples, the percentage dye removal was calculated. The results show that 0.10 gm CP is sufficient for dye removal from 10 ml of 2,5,10 & 20 ppm MB solutions. The efficiency of 0.10 gm CP and 0.01 gm AC was found to be similar. On comparing the price of both of the adsorbents it was concluded that CP can be used as an alternative to AC.