Browsing Department of Physics & Materials Science by Title
Now showing items 77-96 of 158
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Mathematical model of variable speed pitch regulated turbine in a wind energy conversion system
(2014)Pitch control of wind turbine in a wind energy conversion system involves the change of the rotor blade pitch angle along the rotor axis. Most compa-nies are faced with the challenge of maintaining a steady and optimal ... -
Mathematical modelling of the Olkaria Geothermal Reservoir
(School of Mathematics, University of Nairobi, 1996-05)The basic equations which govern the flow of fluids in a geothermal reservoir (often a two-phase mixture of steam. and water) are outlined. The governing nonlinear system of partial differential equations that arises is ... -
Mathematical modelling of wind turbine in a wind energy conversion system: Power coefficient analysis
(2012-01)The world is increasingly going green in its energy use. Wind power is a green renewable source of energy that can compete effectively with fossil fuel as a generator of power in the electricity market. For this effective ... -
Mechanical Properties of Al–Mg–Si Alloys (6xxx Series): A DFT-Based Study
(MDPI, 2023-09-13)Al–Mg–Si alloys are used in aircraft, train, and car manufacturing industries due to their advantages, which include non-corrosivity, low density, relatively low cost, high thermal and electrical conductivity, formability, ... -
Microstructural and Elastic Properties of Stable Aluminium-rich TiAl and TiAl2 Formed Phase Intermetallics
(North-Holland, 2021)We studied aluminium-rich Ti-Al (Ti32Al68 and Ti40Al60) binary alloys that were composed of TiAl and TiAl2 lamellar microstructures. The law of mixtures was employed in calculating the theoretical Young’s moduli. The lattice ... -
Microstructural and elastic properties of stable aluminium-rich TiAl and TiAl2 formed phase Intermetallics
(North-Holland, 2021)We studied aluminium-rich Ti-Al (Ti32Al68 and Ti40Al60) binary alloys that were composed of TiAl and TiAl2 lamellar microstructures. The law of mixtures was employed in calculating the theoretical Young’s moduli. The ... -
Microstructural and elastic properties of stable aluminium-rich TiAl and TiAl2 formed phase Intermetallics
(North-Holland, 2021)We studied aluminium-rich Ti-Al (Ti32Al68 and Ti40Al60) binary alloys that were composed of TiAl and TiAl2 lamellar microstructures. The law of mixtures was employed in calculating the theoretical Young’s moduli. The ... -
Modelling Stratified Flow in an Inclined Flow Channel with a Bend
(International Scientific Press, 2013-07-01)Multi-phase flows modelling in wellbore has always been a problem to the petroleum and many other industries. In the petroleum industry, correlations are presently in use, most of which are obsolete as their application ... -
Multipole expansion of integral powers of cosine theta
(Nature Publishing Group, 2020-11-18)Legendre polynomials form the basis for multipole expansion of spatially varying functions. The technique allows for decomposition of the function into two separate parts with one depending on the radial coordinates only ... -
Near-Exact Non-relativistic Energies for Many-Electron Atoms
(2017-12)Electron-electron interactions and correlations form the basis of difficulties encountered in the theoretical solution of problems dealing with multi-electron systems. Accurate treatment of the electron-electron problem ... -
Nitrogen Doping of Hexagonal and Cubic Ge2Sb2Te5 Nanocrystals: An Ab Initio Study
(World Scientific Publishing Company, 2018)The effect of nitrogen doping on the structural, electronic and optical properties of hexagonal and cubic Ge2Sb2Te5 (GST) has been investigated from first principles. The nitrogen content was set to 10 at.% and 25 at.%, ... -
Nitrogen Doping of Hexagonal and Cubic Ge2Sb2Te5Nanocrystals: An Ab Initio Study
(World Scientific Publishing Company, 2018-12-17)The effect of nitrogen doping on the structural, electronic and optical properties of hexagonal and cubic Ge2Sb2Te5 (GST) has been investigated from first principles. The nitrogen content was set to 10 at.% and 25 at.%, ... -
A note on momentum and energy conservation in dynamics under arbitrary forces in classical Newtonian and relativistic mechanics
(Research gate, 2018)In teaching mechanics course to first year undergraduate students, I have come across a simple, but very important, gap in the formulation of the principle of conservation of momentum and energy in the dynamics of a body ... -
Numerical Computation of Steady Buoyancy Driven MHD Heat and Mass Transfer Past An Inclined Infinite Flat Plate with Sinusoidal Surface Boundary Conditions
(2007)In this paper we study the e ects of magnetohydrodynamics (MHD) uid ow on a two dimensional boundary layer ow of a steady free convection heat and mass transfer on an inclined plate in which the angle of inclination ... -
Numerical Solution of Non-Linear Boundary Value Problems of Ordinary Differential Equations Using the Shooting Technique
(2017)Ordinary Di erential Equations (ODEs) of the Initial Value Problem (IVP) or Boundary Value Problem (BVP) type can model phenomena in wide range of elds including science, engineering, economics, social science, biology, ... -
Numerical solutions of the Burgers’ system in two dimensions under varied initial and boundary conditions
(2012)In this paper, we generate varied sets of exact initial and Dirichlet boundary conditions for the 2-D Burgers’ equations from general analytical solutions via Hopf-Cole transformation and separation of variables. These ... -
A numerical thermal growth model for prediction of microalgae production in photobioreactors
(AIP Publishing, 2016-03)A thermal growth model for microalgae that are not heavier than water with the consideration of heat transfer and growth-temperature dependence in photobioreactor (PBR) is developed. The microalgae growth performance is ... -
Occurrence characteristics of equatorial plasma bubbles over Kisumu, Kenya during Solar maximum of Solar Cycle 24
(International Journal of Advanced Astronomy, 2021)Equatorial Plasma Bubbles (EPBs) are irregular plasma density depletions in the ambient electron density in the equatorial F-region ion osphere generated after sunset. EPBs are known to bring disruptions to telecommunication ... -
On a complex spacetime frame: new foundation for physics and mathematics
(Research gate, 2016)This paper provides a derivation of a unit vector specifying the temporal axis of four-dimensional space-time frame as an imaginary axis in the direction of light or general wave propagation. The basic elements of the ... -
On atomic state purity operator, degree of state purity and concurrence in the JC and anti-JC models
(arxiv.org, 2022)The state of an atom in a bipartite qubit, Jaynes-Cummings (JC) or anti-Jaynes-Cummings (aJC) interaction is described by a reduced density operator. The purity of the state has been measured by taking the trace of the ...