Browsing Department of Physics & Materials Science by Issue Date
Now showing items 21-40 of 158
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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 ... -
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 ... -
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 ... -
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 ... -
MATHEMATICAL INVESTIGATION ON THE EFFECT OF NUMBER OF BRANCHES ON WATER HAMMER
(Pushpa Publishing House, 2013-10-01)This paper looks at water hammer with an emphasis on the number of branches. The mathematics of water hammer are described in a transient condition. This includes the momentum and continuity equations for conduits. A ... -
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 ... -
Investigation of the Effect of Film Thickness on the Optical Properties of Amorphous Se85-xTe15Sbx Thin Films
(Africa Journal of Physical Sciences, 2014)Amorphous thin films of Se85-xTe15Sbx (x = 0.0, 0.5, 2.5, and 5.0 at. %) deposited by flash evaporation technique, have been investigated in the wavelength range of 500nm-3000nm. It is found that the effect of increasing ... -
Quiet Time Geomagnetic Field Variations in the Equatorial East African Region During the Inclining Phase of Solar Cycle 24
(Science Publishing Group, 2014)In the present paper, geomagnetic field data obtained from magnetometer measurements at two ground based stations have been used to study solar activity dependence of the solar quiet variations. The study has focused on ... -
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 ... -
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 ... -
Complex Spacetime Frame: Four-Vector Identities and Tensors
(Scientific Research Publishing, 2014)This paper provides derivation of some basic identities for complex four-component vectors defined in a complex four-dimensional spacetime frame specified by an imaginary temporal axis. The resulting four-vector identities ... -
The benefits and challenges emanating from community policing in Kenya: A Criminological Perspective
(International Journal of Innovation and Scientific Research, 2014)Community policing is an integral component in ensuring that there is no insecurity in the community. More so, the Kenyan government in the Kibaki regime introduced the concept of community policing which was seen as ... -
Optical properties and Raman studies of amorphous Se-Bi thin films
(The African Review of Physics, 2014)Flash evaporated amorphous Se Bi (x = 0, 1, 2, 3, and 4 at. %) thin films of 350 ± 10 thickness have been investigated in the wavelength range of 200nm − 3000nm. It is found that the effect of increasing bismuth ... -
The Question of Elitism, Medium and Audience in African Literature: Examples from Kiswahili Short Story
(Academia.edu, 2014)Since the Makerere Conference of 1962, the question of what is ‘African Literature’ has remained unresolved. To a large extent a great number of scholars led by Ngugi reduced the whole question to that of language. This ... -
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 Critical Overview of the Kenyan Prisons System: Understanding the Challenges of Correctional Practice
(International Journal of Innovation and Scientific Research, 2014)Kenya has been widely criticized for its on-going abuse of human rights and corruption in government administration. Moreover, the prison system in Kenya has been termed to be dilapidated since they were adopted from ... -
Mathematical analysis of tip speed ratio of a wind turbine and its effects on power coefficient
(2014)In this paper we estimate the value of tip speed ratio of a wind turbine and evaluate its effects on power coefficient. The power coefficient, Cp, is achieved at a particular tip speed ratio, β, which is specific to the ... -
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 ... -
Demystifying the Menstruation Process among the Kenyan Girl-Child “A Period of Shame”: A SocioCultural Perspective
(International Journal of Science and Research (IJSR), 2014)This paper provides a critical review of the challenges faced by the girl child during menstruation period. It provides an analysis of various literatures based on these challenges and thus focuses on the Kenyan girl ... -
Optical properties and Raman studies of amorphous se-bi thin films
(The African Review of Physics, 2014)Flash evaporated amorphous Se Bi (x = 0, 1, 2, 3, and 4 at. %) thin films of 350 ± 10 thickness have been investigated in the wavelength range of 200nm − 3000nm. It is found that the effect of increasing bismuth content ...