Open Access Original Research Article

Estimation of Refractivity Gradient and Geoclimatic Factor for Radio Link Design in Nigeria

Israel Emmanuel, Babatunde Adeyemi, Kayode D. Adedayo

Physical Science International Journal, Page 1-9
DOI: 10.9734/PSIJ/2018/34489

Accurate estimation of refractivity gradient and geoclimatic factor is highly necessary for radio signal propagation in clear air environment to cater for fade margin, essential for a reliable radio link. This is necessary because of the unstable nature of the environment the signal is traversing. These parameters were estimated from the meteorological parameters of surface air and dew temperature, temperature and relative humidity obtained from European Centre for Medium-Range Weather Forecasts (ECMWF) archive during the period of 36 years. Point refractivity gradient at 100 m with refractive conditions were estimated for different locations across Nigeria in tropical region. The results show that the seasonal variation experience across the locations were influenced by the movement of inter tropical discontinuity. Values of geoclimatic factor also varies seasonally and geographically. Moderate association exist between β factor and latitude with correlation coefficient of 0.45 which is statistically significant as p<0.05. However, weak or non-relationship exist between β, µ, altitude and longitude as indicated by correlation coefficient.

Open Access Original Research Article

Effect of Silver Nanoparticles Ink on Cerium Titanium Oxide Thin Films

Cliff Orori Mosiori

Physical Science International Journal, Page 1-6
DOI: 10.9734/PSIJ/2018/38745

Wide band gap technology has its challenges. However, such materials include CeTiO2 are known to have a wide band gap of about 3.55 eV. The effort is now directed towards CeTiO2 thin-films by incorporating nanoparticles. Finding wide band gap materials that are both transparent to visible light and electrically conductive for today’s popular devices has now grown it investigating silver naopartilces (Ag NPs) for potential tuning of band gap. In this work, silver nanoparticles were used to dope CeTiO2. To generate CexAg0.02xTiO2, pure cerium oxide, silver metal and titanium dioxide composites were used and it was observed that its thin films possess higher absorption coefficients with a tunable optical band gap varying between 3.42 - 3.78 eV suitable for wide band gap optical applications.

Open Access Original Research Article

Natural Convective Heat Transfer in a Laminar Flow over an Immersed Curved Surface

Charles Mwaniki Nyaga, Mary Wainaina, Osman Shaibu

Physical Science International Journal, Page 1-12
DOI: 10.9734/PSIJ/2018/43567

Numerical solutions of unsteady laminar free flow of a viscous fluid past an immersed curved surface were presented in this research study. The two-dimensional fluid flow in consideration was unsteady and incompressible. Flows of this nature are commonly encountered in engineering studies such as Aerodynamics and Hydrodynamics. In our study, the continuity, the momentum and thermal energy equations were non-dimensionalized and the solutions of the dimensionless governing equations approximated using finite-difference method. The velocity and temperature fields were studied by varying various parameters in the equations governing the fluid flow. The results obtained were presented graphically for comprehensive and easier interpretation. From the results, it was found out that the dissipation of heat within the boundary layer increases with increase in the length of the curvature i.e. when the length of the curvature was increased, a consequence increase in the amount of heat dissipated within the boundary layer was noted.  Also at large Reynolds number, minimal amount of heat dissipated within the boundary layer was recorded. These findings would assist Engineers in making appropriate designs and estimate improvements in equipment that require minimal resistance to the fluid in motion.

Open Access Original Research Article

Experimental Study of the Thermo-physical Properties of Lateritic Blocks Used in the Habitat in Dry Tropical Climate

Emmanuel Ouédraogo, Ousmane Coulibaly, B. Kossi Imbga, P. Florent Kiéno, Abdoulaye Ouédraogo

Physical Science International Journal, Page 1-10
DOI: 10.9734/PSIJ/2018/43887

This article presents an experimental study on the thermo-physical characterization of local materials used in building construction. These materials are laterite cut blocks from three different quarries. The characterization was done with the hot plate device and the asymmetrical method was used. All the samples studied have thermal conductivities less than 0.6 W.m-1.K-1 and thermal diffusivities lower than 3*10-7 m2.s-1. These results show that the materials have good thermal performance.

Open Access Original Research Article

Solutions of Schrödinger and Klein-Gordon Equations with Hulthen Plus Inversely Quadratic Exponential Mie-Type Potential

Ituen B. Okon, Oyebola Popoola, Cecilia N. Isonguyo, Akaninyene D. Antia

Physical Science International Journal, Page 1-27
DOI: 10.9734/PSIJ/2018/43610

We proposed a novel potential called Hulthen plus Inversely Quadratic Exponential Mie-Type potential (HIQEMP). We use  parametric Nikiforov-Uvarov method  to study approximate solutions of   Schrödinger and Klein-Gordon equations with the novel potential. We obtain bound state energies and the normalized wave function expressed in terms of Jacobi polynomial. The proposed potential is applicable in the field of vibrational and rotational spectroscopy. To ascertain the accuracy of our results, we apply the nonrelativistic limit to the Klein-Gordon equation to obtain the energy equation which is exactly the same as nonrelativistic Schrodinger energy equation. This is a proof that relativistic equation can be converted to nonrelativistic equation using a nonrelativistic limit with the help of Greene-Aldrich approximation to the centrifugal term. The wave functions were normalized analytically using two infinite series of confluent hypergeometric functions. We implement MATLAB algorithm to obtain the numerical bound state energy eigen-values for both Schrödinger and Klein-Gordon equations. Our potential reduce to many existing potentials and the result is in agreement with existing literature. The energy spectral diagrams were plotted using origin software. The bound state energy from Schrodinger equation decreases with increase in quantum state while that of Klein-Gordon equation increases with increase in quantum state.