Browsing Department of Physics & Materials Science by Title
Now showing items 38-57 of 158
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Dewetting Rheology for Determining Viscoelastic Properties of Nonequilibrated Thin Polymer Films
(American Chemical Society, 2019)We performed systematic dewetting experiments on isotactic poly(para-methylstyrene) (iPpMS) films to explore the temperature dependence of the viscoelastic behavior of these films. We quantified the amount of residual ... -
A Direct Calculation of First-Order Wave Function of Helium
(IOP Publishing, 2010)We develop a simple analytic calculation for the first order wave function of helium in a model in which nuclear charge screening is caused by repulsive coulomb interaction. The perturbation term, first-order correlation ... -
Effect Of Deposition Temperature On The optical Properties Of Iron-Doped Cadmium Stannate Thin Films Deposited By Spray Pyrolysis
(IJSTRE, 2019): 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 ... -
Effect of Ga Incorporation and Film Thickness on the Optical Properties of as-Deposited Amorphous GaxSel-x Thin Films
(University if Nairobi Research archive, 2014)Flash evaporated amorphous GaxSe1-x (x = 0, 1, 2, 3, and 4 atomic %) on glass substrates have been investigated within a 500nm-1500nm spectral range. Film thicknesses explored were ; 200±10nm, 265±10nm, 330±10nm, and ... -
Effect of Reverse Bias on Dye-Sensitized Technology: Lessons for Application in PV-Integrated Textile Fabric Designs Useable in Wajir, Vihiga, Kitui and Kajiado Counties in Kenya
(Journal of Technology Innovations in Renewable Energy, 2018)This paper reports on the effect of reverse bias (RB) on dye-sensitized solar cells (DSSCs) that were investigated outdoor in Wajir (1o4450 North, 40o 4 8 East), Vihiga (35o0 East, 0o15 North), Kitui (3o 0 South, 37o 50 ... -
The effect of temperature and time on the properties of 2D Cs 2 ZnBr 4 perovskite nanocrystals and their application in a Schottky barrier device
(Royal Society of Chemistry, 2021)2D hybrid perovskites are promising materials for solar cell applications, in particular, cesium-based perovskite nanocrystals as they offer the stability that is absent in organic–inorganic perovskites. However, the most ... -
Effects of Conduction and Variable Properties On a Two Dimensional Conjugate Heat Transfer of a Nanofluid in a Microchannel
(International Scientific Press, 2013-10-01)In this paper we analyze the effects of conduction and variable properties on a two dimensional conjugate heat transfer of a nanofluid containing a mixture of two fluids namely, Aluminium oxide (Al2O3) and water. Nanoparticles ... -
Elementary partial differential equations
(Lambert, 2013-06-01)The importance of partial differential equations cannot be gainsaid. They are used in science and engineering. Many natural phenomena such as sound, heat, electrostatics, electrodynamics, fluid flow etc occurring in science ... -
Energy Resources in East Africa
(Springer, Cham, 2015)When talking about East Africa, traditionally this refers to the states of Kenya, Uganda and Tanzania with a combined population of over 120 million people in 2014. The three countries have a long history of association ... -
Energy Source and Technology Options for Kenya: Towards Direct Conversion of Solar Energy to Mechanical Work
(2017)Sunlight though not heat, has inherent potential for direct conversion to mechanical work, just as heat does. The Physics pitching the possibility of direct conversion of nearly the entire sunlight received by a system ... -
Enhancing climate action at grassroots levels in least developed countries: unlocking bio-briquetting opportunities for communities in Wajir, Vihiga, Kitui, and Kajiado counties in Kenya
(Inderscience Publishers (IEL), 2021)Grassroots communities are often the hardest hit by climate change. They also appreciably contribute to the problem through activities like deforestation, land use changes, and cooking with firewood. Bio-briquettes from ... -
Enhancing light absorption and lifetime stability of organic solar cells using pentacene encapsulation
(SA Institute of Physics, 2015). In the present work we compare the performance of a pristine P3HT:PCBM based bulk heterojunction solar cell with a device incorporated with pentacene encapsulated Ag nanoparticles. Encapsulation has been achieved through ... -
AN ESTIMATE OF VELOCITY PROFILE IN LAMINAR BOUNDARY LAYER
(Academic Publications, Ltd., 2011-09-02)This paper examines the boundary layer thickness developed for an incompressible viscous fluid flowing over a flat plate. The solution of the Blasius problem is considered. In this paper, the authors propose a polynomial ... -
Evaluating the effect of the substrate on the electrocatalytic performance of Cu2ZnSnS4 and Cu2ZnSnSe4 counter electrodes in dye-sensitized solar cells
(Elsevier, 2022)The colloidal synthesis of Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) nanoparticles and their application as counter electrodes in dye-sensitized solar cells (DSSCs). In particular, the effect of three substrates namely; ... -
Exact analytical solutions for fully quantized parametric oscillation dynamics
(Routledge, 2013)In this paper, a simple method for obtaining general analytical solutions of the time evolution equations for a fully quantized parametric oscillation process is developed. Heisenberg’s equations for the signal–idler photon ... -
Finite Difference Analysis of 2-Dimensional Acoustic Wave with a Signal Function
(2015-12-09)This paper describes progress on a two dimensional numerical simulation of acoustic wave propagation that has been developed to visualize the propagation of acoustic wave fronts and to provide time-domain signal. In this ... -
First Order Expectation Values of Electron Correlation Operators for Two-Electron Atoms
(SPG, 2015)Simple analytic first-order wave functions corresponding to two-electron atoms electron correlation operators are obtained by reduction of the Rayleigh-Schrödinger first order perturbation equation to that of one-electron ... -
Flow of a Self-Similar Non-Newtonian Fluid Using Fractal Dimensions
(MDPI, 2022)In this paper, the study of the fully developed flow of a self-similar (fractal) power-law fluid is presented. The rheological way of behaving of the fluid is modeled utilizing the Ostwald–de Waele relationship (covering ... -
Fundamental quantum noise in a fully quantized degenerate parametric amplification process
(Research gate, 2016)An exact analytical solution of the time-dependent Schroedinger equation for a fully quantized degenerate parametric amplification process generated by quantized multi-mode pump photons provides a quantized multi-photon ... -
General analytical solution for the one dimensional regular Cauchy problem of Euler-Poisson-Darboux equation
(Hikari Ltd, 2017)A general analytical solution to the one dimensional regular Cauchy problem of Euler-Poisson-Darboux (EPD) equation has been investigated. The one dimensional EPD which is a Partial Differential Equation (PDE) with initial ...