Browsing Department of Physics & Materials Science by Title
Now showing items 124-143 of 158
-
SCINDA-GPS derived TEC depletions and amplitude scintillations over Kisumu, Kenya during selected quiet and storm days of 2013 and 2014
(International Journal of Advanced Astronomy, 2020)Total Electron Content (TEC) depletion and amplitude scintillation (S4) can be derived from, SCINDA-GPS receivers situated in various parts of the equatorial region. In this paper we present results of characterization ... -
Shell structure of the SU (N) generator spectrum: interpretation as spin angular momentum operators
(Research gate, 2020)We have established that SU(N) symmetry group generators occur in a spectrum with a quantum structure composed of N − 1 configuration shells each containing a definite number of symmetric and antisymmetric pairs of ... -
Similarity Transformation Analysis of Heat and Mass Transfer Effects on Steady Buoyancy Induced MHD Free Convection Flow Past an Inclined Surface
(2017)The present work is devoted to the problem of a steady two di- mensional hydromagnetic convective ow of a viscous, incompressible electrically conducting uid past an inclined semi-in nite plate in the presence of ... -
Solutions of second-order partial differential equations in two independent variables using method of characteristics
(nternational Journal of Engineering and Mathematical Sciences, 2013-06-01)In this paper we have classified second order linear PDEs into three types, hyperbolic, parabolic and elliptic. Hyperbolic equations have two distinct families of (real) characteristic curves, parabolic equations have a ... -
Some new features of photon statistics in a fully quantized parametric amplification process
(Scientific Research Publishing, 2014)An exact quantum treatment reveals that signal and idler photon number operators are not wellbehaved dynamical operators for studying photon statistics in parametric amplification/downconversion processes. Contrary to ... -
: Spray Pyrolysis Technique (SPT) was used to deposit thin films (TFs) of cadmium stannate, doped with iron (Fe) for the first time. The precursor solutions that were used wereprepared at a concentration of 0.1M, doped with Feand then sprayed onto the pre-heated glass slides immediately at deposition temperatures of 350 ± 7°C, 400 ± 7°C and 450 ± 7°C. The optical properties of the deposited Fe-doped TFs were studied in the wavelength range of 300-1100nm. The X-Ray diffraction (XRD) studies showed that the TFs were orthorhombic with growth orientation along the (2 0 0) direction. Film thickness of 85 ± 10 nm was obtained. It was found out that anincrease in the deposition temperature increased transmittance and band gap, but decreased absorption coefficient, extinction coefficient and refractive index, which was attributed to the improvement in crystallinity of the deposited TFs. Doping reduced transmittance and band gap, but increased refractive index, absorption coefficient and extinction coefficient, which was attributed to the increase in free carriers. KEYWORDS:cadmium stannate, deposition temperature, iron-doped, optical properties of cadmium stannate
(Elsevier, 2020)The elastic properties of the orthorhombic cadmium stannate (Cd2SnO4) were investigated using density functional theory, applying both energy-strain relationship (which is found in the literature) and stress-strain ... -
Stability Investigation in the Optical Properties of Thermally Evaporated Ge5Se95-x Znx Thin Films
(University of Nairobi, Kenya, 2015)Selenium-based chalcogenides are useful in telecommunication devices like infrared optics and threshold switching devices. The investigated system of Ge5Se95-xZnx (0.0 ≤ x ≤ 4 at.%) has been prepared from high purity ... -
Steady MHD poiseuille flow between two infinite parallel porous plates in an inclined magnetic field
(2012)In this paper, we examine the motion of a two dimensional steady flow of a viscous, electrically conducting, incompressible fluid flowing between two infinite parallel porous plates under the influence of transverse magnetic ... -
Structural and Mechanical Properties of NbN Alloyed with Hf, In, and Zr for Orthopedic Applications: A First-Principles Study
(MDPI, 2024-01-17)The search for biocompatible, non-toxic, and wear-resistant materials for orthopedic implant applications is on the rise. Different materials have been investigated for this purpose, some of which have proved successful. ... -
Structural and Mechanical Properties of theTi32Al68 and Ti40Al60 Binary Alloys: Experimental and computational Studies
(Elsevier, 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 ... -
Structural and Optical Probe into Rare Earth Doped ZnO for Spectral Conversion in Solar Cells
(Jenny Stanford Publishing, 2022)This chapter examines the relationship between structure and optoelectronic properties of rare earth doped Zinc oxide (ZnO) thin films fabricated by RF magnetron sputtering for photovoltaic applications. A doped ZnO layer ... -
Structural and spectroscopic analysis of ex-situ annealed RF sputtered aluminium doped zinc oxide thin films
(AIP Publishing LLC, 2017)Aluminium doped zinc oxide thin films are prepared by Radio Frequency magnetron sputtering in pure argon atmosphere at 100 W. The structural results reveal good film adhesion on a silicon substrate (001). The thin films ... -
A study of the Equatorial Ionosphere over Nairobi During selected magnetically disturbed and quiet times for the year 2009 Using co-located instruments
(ARC, 2014)Investigation of the behavior of the Equatorial Ionosphere over Nairobi-Kenya within the East Africa region is done using co-located instruments, that is, SCINDA-GPS system and a Magnetometer ( MAGDAS). This was done for ... -
A study of the Equatorial Ionosphere over Nairobi During selected magnetically disturbed and quiet times for the year 2009 Using co-located instruments
(IJARPS, 2014)Investigation of the behavior of the Equatorial Ionosphere over Nairobi-Kenya within the East Africa region is done using co-located instruments, that is, SCINDA-GPS system and a Magnetometer ( MAGDAS). This was done for ... -
SU (N) generator spectrum
(Research gate, 2018)This paper provides an accurate mathematical method for determining SU(N) symmetry group generators in a general N-dimensional quantum state space. We identify the generators as well-defined quantum state transition and ... -
Supporting Information for: Rheological Properties of Blends of Isotactic Polystyrene–
(2013)Figure S1: Optical micrographs and atomic force microscopy (AFM) images for the 95% iPpMS–5% iPS binary system dewetted at 𝑇dew= 240℃ and at different incubation times.(a) shows a 200 nm film before the dewetting ... -
Symmetry conjugates and dynamical properties of the quantum Rabi model
(Cornell University, 2021)Symmetry transformations have proved useful in determining the algebraic structure and internal dynamical properties of physical systems. In the quantum Rabi model, invariance under parity symmetry transformation has been ... -
Symmetry Dependent Analytical Pseudopotential for Helium Atom
(2019-11-11)Electron-electron interaction is the origin of the many-body problems usually encountered in physics and chemistry. Helium atom and other two-electron systems are the simplest many-body systems in nature. The Schr¨odinger ... -
Technology Options for the Built Environment in Kenya: Dye- Sensitized and Amorphous Silicon Photovoltaics for Application in NZE Buildings
(Bentham Science Publishers Ltd., 2017)Background The performance of a Dye-Sensitized Solar Module (DSSM) has been investigated under different outdoor air mass (AM), irradiance intensity and temperature conditions in Wajir, Kitui, Vihiga and Kajiado Counties ...