Browsing Theses and Dissertations by Title
Now showing items 488-507 of 513
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Theoretical Study of Current-Induced Dynamics of an Antiferromagnetic Skyrmionium
(2019-06-22)In this thesis, we present a theoretical study on the current-induced nucleation and propagation of antiferromagnetic skyrmionium. A skyrmionium, also known as 2π-skyrmion, is a vortex-like magnetic structure characterized ...
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Thermal Transient Testing Using Tds Technique
(2011-12-12)In the estimation of most reservoir parameters in well test, the reservoir is assumed to be isothermal which is practically not true due to the fact that there are heat sources due to friction in the wellbore, works done ...
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Thermodynamic Analysis of Unsteady Mhd Boundary Layer Flow With Slip Over a Permeable Surface
(2016-06-12)Magnetohydrodynamics (MHD) boundary layer flow problems have become important in industrial manufacturing processes such as plasma studies, chemical engineering, electrochemistry, polymer processing, petroleum industries, ...
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Tight Binding Descriptions of Graphene and Its Derivatives
(2017-12-20)Graphene is an effectively two dimensional form of carbon atoms arranged in honeycomb lattice. Due to its lightweight, high electron mobility and other special electronic properties it is considered both an academically ...
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Topological Antiferromagnetic Magnons
(2019-07-12)We have studied a model for a non-collinear but coplanar antiferromagnetic spin texture on a two dimensional kagome lattice structure in the presence of Dzyaloshinskii-Moriya Interaction (DMI). We observed some interesting ...
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Towards a New Exchange-Correlation Density Functional for more Accurate Band Gap Predictions
(2016-06-17)Density-Functional Theory (DFT) offers a simplification to electronic structure problems by using the electron density instead of the wave-function. Unlike the wave-function which is a function of 3N variables (excluding ...
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Towards a Unifying Framework for Engineering Devs Distributions Simulation
(AUST, 2017-12-10)Simulation engineering employs the use of simulation models, simulation environments, and simulation execution platforms in providing applicable Modeling and Simulation (M&S) solutions for studying complex systems. Discrete ...
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Trust Aware Recommender System for Social Coding Platforms (GitHub Case Study)
(2017-11-12)Social networking systems have found their way into all sectors of life. With the advent of social coding platform like GitHub, networks of developers can be inferred based on the projects they participated in. When a new ...
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The Tuning of the Todd and Longstaff Mixing Parameter in Limited Compositional Simulation to Optimize Recovery from a Gas Condensate Reservoir
(2021-07-16)A gas condensate reservoir is a type of gas reservoir that exists when the reservoir temperature is between the critical temperature and the cricondentherm. Compositional simulators are used to simulate these types of ...
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The Tuning of the Todd and Longstaff Mixing Parameter in Limited Compositional Simulation to Optimize Recovery from a Gas Condensate Reservoir
(2021-07-20)A gas condensate reservoir is a type of gas reservoir that exists when the reservoir temperature is between the critical temperature and the cricondentherm. Compositional simulators are used to simulate these types of ...
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Ultrafast X-rays Imaging For Medical Physics
(2016-06-17)In this thesis we explored the production of highly coherent and energetic extreme ultra violet(XUV) radiation through the process of high harmonic generation(HHG). HHG is a process by which a ultrashort laser pulse interact ...
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Uncertainty Analysis in Simulation for Reservoir Management: Case Study from Niger Delta
(2016-04-13)Uncertainty analysis of flow performance predictions involves identifying significant reservoir parameters impacting the flow response. Uncertainty analysis often requires conducting large number of reservoir simulation ...
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Upgrading Low-Grade Iron Ore by Magnetizing Roasting using Sawdust
(2021-03-16)Low-grade iron ore sample was collected from Gangra mines in Nimba Liberia. The ore was subjected to XRD and XRF analysis and was found to contain 63.1% Fe2O3, 25.4% SiO2, 9.1% Al2O3, and 2.4% LOI. 561.5 g . 1684.5g raw ...
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Upgrading Low-Grade Iron Ore by Magnetizing Roasting using Sawdust
(2021-03-23)Low-grade iron ore sample was collected from Gangra mines in Nimba Liberia. The ore was subjected to XRD and XRF analysis and was found to contain 63.1% Fe2O3, 25.4% SiO2, 9.1% Al2O3, and 2.4% LOI. 561.5 g . 1684.5g raw ...
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Upstream Petroleum Industry Performance Evaluation using Data Envelopment Analytic Approach
(2019-06-23)Nigeria ranks among the top ten petroleum producers in the world with over eighty petroleum Investors in its upstream sector. This creates an enormous challenge for the upstream institutions’ managers especially in the ...
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Utilisation of Rice Husk Ash (RHA) in the Production of Magnesium Oxide (MgO)-BASED Cement
(2017-10-23)The use of Magnesium oxide (MgO) cement as a full replacement and viable alternative for Ordinary Portland Cement was studied. Rice husk, an agricultural waste, was calcined and synthesised to be used as a source of silica ...
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Utilization of Machine Learning for Flow Assurance in the Oil and Gas Sector: a Focus on Annular Flow Prediction
(2021-07-12)There is insufficient literature for annular flow and applications of Machine Learning in the petroleum industry; thus, this thesis is centred on annular flow prediction. Liquid holdup and flow behaviour during annular ...
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Valorization of Agro-Waste for Mechanical Properties’ Improvement of Lateritic Soil for Sustainable Construction
(AUST, 2020-09-06)This study presents the results of a combined theoretical, experimental and statistical study of the mechanical performance of stabilized lateritic soil for sustainable construction applications. The lateritic soil was ...
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Variational Inequality in Hilbert Spaces and their Applications
(2019-06-23)The study of variational inequalities frequently deals with a mapping F from a vector 0 space X or a convex subset of X into its dual X . Let H be a real Hilbert space and a(u, v) be a real bilinear form on H. Assume that ...
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Vertical-Horizontal Permeability Relationships in Stress and Non Stress Sensitive Reservoirs
(2011-12-12)One of the important petrophysical parameter in reservoir description is the permeability distribution in a given reservoir. It is well known that most reservoir are heterogeneous in nature and homogeneous ones been the ...