2023

Permanent URI for this collection

https://escholar.umt.edu.pk/handle/123456789/16489

Browse

Browsing 2023 by Issue Date

Filter results by year or month
Now showing 1 - 10 of 10
  • Thumbnail Image
    Item
    Ternary metal oxide with carbon composite as high-performance electrode materials for supercapacitor applications
    (UMT, Lahore, 2023) Shama Rao
    In this study, three samples of MOF-derived ternary iron-nickel–cobalt ZIF-67 composite (FeNiCo ZIF-67) is synthesized via co-precipitation method with the variation in molar concentration of FeO, NiO and CoO. Electrode fabrication has been carried out for these three samples. Ternary metal oxides ZIF 67 have gained attention for supercapacitor electrode material due to high surface area, porosity, chemical stability, tunable properties, redox activity and ecofriendly material. The porous polyhedral structure of FeNiCo ZIF-67 with different compositions consisting of interconnected nanoparticles is found to play an important role in increasing the charge storage capacity of the material. Considered crucial to a robust and sustainable energy future, their importance spans economics, ecology, and society. Several characterizations, including X-ray diffraction, Energy dispersive X ray, Transmission electron microscopy and Raman are used to characterize the morphology, structure, and composition of these materials, and electrochemical methods, such as cyclic voltammetry (CV), galvanostatic charge and discharge (GCD), and electrochemical impedance spectroscopy (EIS), are also used to evaluate the electrode performance. The FeNiCo ZIF-67 (1:2:1) electrode material exhibits an outstanding specific capacitance of 532.7 F/g at a current density of 1 A/g, as compared to the other materials FeNiCo ZIF-67 (1:1:1) and FeNiCo ZIF-67 (2:1:1) These investigations provide an easy and efficient method to develop nanocomposites FeNiCo ZIF-67 (1:2:1) with better electrochemical characteristics, as electrode materials for supercapacitor applications.
  • No Thumbnail Available
    Item
    Green synthesis of silver nano-particles using dracaena trifasciata extract
    (UMT, Lahore, 2023) AAQIL HUSSAIN
    There is an increasing industrial need for nanoparticles because of their wide pertinency in several fields like electronic engineering, catalysis, chemical engineering, power, and therapeutic treatment etc. Metal nanoparticles have been usually synthesized through aquatic chemical techniques. The precursors used in those techniques are highly toxic and flammable. In current research, a cheap and ecological friendly method of green synthesis has been proposed for the preparation of silver nanoparticles from silver nitrate solution by using the extract of Dracaena Trifasciata leaves as reducer. We also have used one chemical and one organic agent for capping. The structural, morphological, optical, and chemical characteristics of the synthesized nanoparticles have been analyzed using X-ray crystallography, SEM, UV-Visible spectroscopy and FTIR. XRD analysis of nanoparticles confirmed the development of face-centered cubic structure and phase purity. No additional peaks of foreign impurities have been observed in XRD spectra. The SEM micrographic analysis revealed that silver nanoparticles have smooth sphere-shaped surface. Due to the coating of protective agent, the edges of the crystallites have been brighter than the cores, causing prepared nanoparticles to be in oval and elliptical shapes. The change in internal parameters (e.g., lattice constant, interplanar spacing, broadening and shifting in XRD peaks) and the rise of absorption in the Uv-Vis spectra signified the capping and reduction of silver nanoparticles. Fourier transform infrared spectroscopy confirmed the existence of functional groups and chemical bonds in samples. Such a silver nano particles can be used in electronic devices as they exhibit excellent electrical conductivity, can also use for chemical stabilities, antimicrobial properties etc.
  • Thumbnail Image
    Item
    Structural and dielectric properties of MgFe2O4 nanoparticles prepared by hydrothermal method
    (UMT, Lahore, 2023) Anam Anwer
    Magnesium iron oxide nanoparticles have sparked the interest of scientists due to their possible applications in spintronic devices. The hydrothermal technique is used to prepare Magnesium iron oxide nanoparticles with varying molarity as 0.1M, 0.2M, 0.3M, 0.4M & 0.5M. The prepared samples are characterized by X-ray Diffractometer (XRD), Vibrating Sample Magnetometer (VSM) and Impedance Analyzer. Mixed phases of (MgFe2O4 + Fe2O3) are observed for 0.1M, 0.2M and 0.5M. Whereas, cubic MgFe2O4 phase is observed at molar concentration of 0.3M and 0.4M. The highest value of crystallite size i.e. 19.5 nm with lowest value of dislocation density and strain are observed for the pure magnesium iron oxide nanoparticles cubic phase at 0.4M. M-H loop exhibits the soft-ferromagnetic behavior for all the samples. Dielectric constant and tangent loss show normal dispersion behavior. Cole-Cole plots show single semicircle indicating high resistance of grain boundaries. The magnesium iron oxide nano powders can be used as potential candidate in spintronics and data storage devices.
  • Thumbnail Image
    Item
    Cosmic-ray modified shock wave type solutions in the presence of alfvén waves
    (UMT, Lahore, 2023) Irshad
    When cosmic rays propagate through a plasma, they can excite hydromagnetic waves through streaming instability. There are energy exchanges among the thermal plasma, cosmic rays, and waves. If the energy density of the cosmic rays and waves is compa rable to that of the thermal plasma (e.g., in the ISM of our Galaxy), the dynamics of the plasma will be affected by the cosmic rays and waves. It is convenient to study the dynamics of the system under a hydrodynamical model. Cosmic rays and waves are considered massless fluids but with comparable energy density to thermal plasma. The system has several energy exchange mechanisms among the four components. We will study the cosmic-ray plasma system by deploying a hydrodynamic approach, this system contains thermal plasma, cosmic rays, and two oppositely propagating Alfven waves. The mentioned approach is an excellent approximation to study the structure and dynamics of the system. We will focus on the steady state of the system in this thesis, especially, structures with continuous or smooth profiles. Energy is transferred by three mechanisms between different components. The mechanisms consist of work done by plasma flow against pressure gradients, cosmic-ray streaming instability, and stochastic acceleration. The interaction between different energy exchange mechanisms can produce different structures. They may be divided into two types : one looks like the test-particle picture and the other looks like a modified shock. In this thesis we just work on modified shocks. In the presence of two oppositely propagating Alfven waves mostly the profiles are non-monotonic, while the system without Alfven waves has monotonic profiles like flows velocity and pressure profiles.
  • Thumbnail Image
    Item
    A geant4 study of optimization of energy and number of primaries in a neutron source
    (UMT, Lahore, 2023) Mamoona Khalid
    Geant4 is widely used to studying the simulations of optimization of neutron source. When any light isotope hit by alpha particles, neutrons are produced. In this work, calculations are carried out with the help of Monte Carlo Methods for which a geometry setup of a neutron source composed of a cylinder (absorber) has been constructed and optimized in the Geant4 code. A complete list of physics processes has also been registered in the code for the generation of neutrons production. This work is to simulate and plots energy deposited in the interaction volume consisting of an absorber and a container. The flux of particles which are leaving this volume has also computed. The energy spectra of emerging particles He3, alpha, anti-nu-e, deuteron, e-, e+, gamma, neutron, nu-e, proton, triton etc have been managed by G4AnalysisManager and its Messenger. The Physics has also discussed for the 12 histograms i.e. total energy deposit, total kinetic energy flow, energy spectrum of emerging e+-, neutrons, protons, deuterons, alphas, ions, baryons, mesons, and leptons (neutrinos). For the optimization, number of primaries were first kept constant at 105 and particle gun energy was only changed to 10 eV, 10 MeV, 10 GeV and 10 TeV. Furthermore, later fixing the value of energy of particle gun at 10 TeV, the effect of decreased in the number of primaries i.e., 103 on energy spectra of all emerging particles are compared with the previous energy spectra with number of primaries 105.
  • Thumbnail Image
    Item
    Continuous solutions of cosmic-rays and waves in astrophysical environments
    (UMT, Lahore, 2023) Kinza Irshad
    The interaction of cosmic rays with thermal plasma in the presence of magneic field have great importance in Astrophysical environment. The interaction of different components available in intersteller medium are not yet completely understood. From the last few decades, this problem becomes important when we discuss the interaction of cosmic rays with plasma in space, such as interstellar clouds. We consider our system as a four-fluid system in which we have thermal plasma, cosmic rays, and two opposite propagating Alfvén waves. We investigate the dynamics and different energy exchange mechanisms of the system. We study the importance of different pressure gradients and their impact on feedback in astrophysical environments. Additionally, cosmic rays diffusion within the plasma is considered along the field lines
  • Thumbnail Image
    Item
    Antibacterial properties of calcium oxide nanoparticles synthesized by hydrothermal method
    (UMT, Lahore, 2023) Nusrat Siddique
    Hydrothermal method is cost effective and reproducible technique for synthesizing nanoparticles of various types. Calcium oxide nanoparticles (NPs) are found to be most versatile type of materials that can be beneficial for electronic and biomedical applications. Choice of application depends on its various structural phases and their thermal, chemical and physical stability. In this study calcium oxide (CaO) nanoparticles were successfully prepared at 0.1M using hydrothermal method. XRD result confirmed cubic phase of calcium oxide. The SEM micrograph showed the uniform distribution along with well-defined grain boundaries in CaO nanoparticles. Calcium oxide nanoparticles exhibited strong antibacterial properties against pathogenic bacteria. Antibacterial activity shows maximum zone of inhibition (~24mm) against Bacillus subtilis species. Thus, present study shows that calcium oxide nanoparticles are non-toxic in nature and can be used in biomedical applications.
  • Thumbnail Image
    Item
    An attempt to explicate the influence of pressure on PrFeO3 ferromagnet for spintronic devices using DFT approach
    (UMT, Lahore, 2023) M. Naeem Nawaz
    A theoretical analysis of the structural, elastic, mechanical, thermal, and electronic properties of the magnetic perovskite PrFeO3 under pressure (0-50) GPa is given in this paper. Based on common stability criteria such as energy optimizations, tolerance factor, and mechanical stability requirements, the examined structures demonstrated stable responses. When compared to accessible literature, the standard structural characteristics have demonstrated outstanding comparative dependability, particularly under ambient settings. Mechanical investigation has revealed that the modulus of elasticity improves structural stability and is linearly related to applied pressure. Furthermore, the pressure treatment revealed the ductile character of the compounds as well as improved conducting capabilities. Both compounds have showed a band gap transition from indirect to direct phase in agreement with the Moss Burstein shift in electronic characteristics.
  • Thumbnail Image
    Item
    Exact solution of Oldroyd-B fluid using Laplace transformation
    (UMT, Lahore, 2023) Muhammad Zubair
    The purpose of this thesis is to analyze the flow of an Oldroyd-B fluid. Results are obtained by the Laplace transformation method. The aim is to check how shear stress, fluid velocity, and fluid temperature are related and which parameters affect Oldroyd-B fluid velocity. The effect of thermal Grashoff number Gr and Mass Grashoff number Gm on the fluid velocity has been shown in this thesis. The effect of Prandtl number Pr on fluid velocity, fluid temperature, and fluid viscosity has been observed in this thesis. All the results satisfy imposed initial and boundary conditions
  • No Thumbnail Available
    Item
    The investigation of structural, electronic and optical properties of full-Heusler Ca2AsAu alloy
    (UMT, Lahore, 2023) Filza Wajid
    Spintronics/magneto electronics brought the scientific research to the Heusler and full-Heusler compounds, since several among them have been shown to be half-metals. Ca2AsAu Heusler alloy has been investigated in the current study in terms of its structural, electronic, and optical properties with the help of the full potential linearized augmented plane wave method (FP-LAPW) approach within the carcass of Density Functional Theory or Ab-initio calculation. All physical and other properties of Ca2AsAu Heusler Alloy is computed with Modified Becke Johnson (mBJ) potential. Modified Becke Johnson (mBJ) potential is preferred over GGA because it gives results very close to the experimental data. Electronic properties are computed with mBJ and we observed that the alloy has semi-conducting behavior with indirect bandgap. Total density of states (TDOS) and partial density of states (PDOS) of the alloys has also determined to check the individual distribution and energy distribution of all the states. Many optical properties including dielectric function, refractive index, optical conductivity, and energy loss are determined. From the calculated optical properties, we can nominate our alloy as good candidate for optoelectronic applications. In particular, due to its semiconductor behavior and favorable optical properties, Ca2AsAu has the potential to be used in the heat sensors, thermal imaging, night vision equipment's and optical fiber, etc.