ABSTRACT This work considered the unsteady state drainage of fluid from a vertical column of porous material of varying porosities in an attempt to verify 'variation of drawn dawn surface with porosity and time using riverbed sand. Kerosene was used as the flowing fluid: Mathematical assumptions ware made in connection with Ducy's law.
ABSTRACT Experimental investigations have shown that variation of porosity and hydraulic gradient are responsible for the deviations from Darcy's law, which is perfectly obeyed only when the fluid flow is laminar in porous media. Previous attempts to modify this equation considered only the effects of porosity of surface-active materials such as clay in causing deviations from Darcy's law. In this study, both the effect of porosity of any porous medium and hydraulic gradient from recent exper...
ABSTRACT The prediction of Large Earthquakes (LE) constitutes a global challenge. Several methods of earthquake prediction including Pattern Recognition (PR) have been proposed but sometimes produce patterns that are not suitable. Occurrence of earthquakes is always assumed to be random when these methods produce unreliable pattern. The fact that these patterns considered to be random could be chaotic (predictable but difficult) has not been investigated. This study was designed to use chaos...
ABSTRACT Using IVL PM2.5 and PM10 particle samplers, airborne particulate matter was sampled from Ashaiman, 30 km from Accra-capital of Ghana. The airborne particles were collected on Teflon filters for a period of three months. In addition to determination of particulate mass in the two fractions by gravimetrical method, aerosol filters were analyzed to determine black carbon (BC) concentration levels using the black smoke method. BC fractions in fine and coarse, together with PM2.5 to PM10 ...
ABSTRACT Acoustic effects such as absorption/amplification of acoustic phonons, Acoustoelectric Effect (AE) and Acoustomagnetoelectric Effect (AME) were studied in Carbon Allotropes. In this thesis, the Carbon Allotropes considered are Graphene Nanoribbon (GNR), 2-dimensional Graphene sheet, and Carbon Nanotubes (CNT). The Boltzmann transport equation (BTE) and the phonon kinetic equation (PKE) were used. All results were analysed numerically and graphically presented. Using BTE for Armchair...
ABSTRACT Potable water supply in Ado-Ekiti is inadequate resulting in increased demand for groundwater in the metropolis. Geologically, Ado-Ekiti is underlain by hydrogeologically challenging crystalline basement rocks whose hydraulic properties are characterised by extreme variations over short distances. Prospective groundwater zones are poorly defined in the hard rock terrain. A thorough and definitive evaluation of the overall groundwater resource in such terrain is imperative. This study...
ABSTRACT The use of chemical fertilizers to replenish depleted soil nutrients due to over cultivation and erosion is a common practice. Natural radionuclides in these fertilizers can cause some radiological adverse health effects to animal, through indirect ingestion of fertilizer, including consumption of plants grown with fertilizers. Information on the level of contribution of chemical fertilizers to farm soil radioactivity and radiological health effects in Nigeria are scanty. This study ...
ABSTRACT Pneumatic Transfer System (PTS) is an auxiliary system of Ghana Research Reactor -1 (GHARR-1) to transfer sample capsule in and out of the reactor irradiation sites. The PTS controller unit design and construction was carried out because the transfer system was not designed to operate in cyclic Neutron Activation Analysis (NAA) and as a result could not determine radionuclides whose half-lives are equal or less than 100 seconds. In addition, most of the components used to design th...
ABSTRACT This paper presents the relationship between thermo f7hysical properties (thermal conductivity and thermal diffusivity) and heavy metal concentration of some surface clay from six local governments in Ibaaun, oyo state, Nigeria. An atomic absorption spectrometer (AAS) 1i1i)as used in analping the concentration of heavy metals present in each sample by .measuring the intensity of external radiation absorbed by the atom produced from the same sample at a wavelength characteristic to th...
ABSTRACT The Boltzmann kinetic equation was used to investigate and derived theoretically the current density characteristics of carbon nanotubes exposed simultaneously to both constant (dc) and high-frequency (ac) electromagnetic fields. Generation and amplification of terahertz radiation at room temperature was predicted. We demonstrated that this can suppress electric current instabilities while still preserving a broadband THz gain. We have further shown that THz gain in the conditions o...
ABSTRACT A three-dimensional (3D) laser imaging system based on digital holography has been used as a tool for testing digital holography (DH) in the infrared (IR) range in several configurations; transmission and reflection mode. The feasibility of digital holography in the infrared region was demonstrated using two beam interferometric technique for recording holograms both in reflection and transmission type geometry which employs a pyroelectric sensor array detector. The materials used ...
ABSTRACT Leaf area measurement can be a time consuming process and may require sophisticated electronic instruments. The objective of this research was to develop a simple, and less time consuming method for leaf area (LA) estimation of some leaves of cassava varieties. A method based on the beta mass absorption coefficient of the leaf has been developed and used for the estimation of leaf area of three varieties of cassava and the accuracy and precision of this method has been compared with ...
ABSTRACT The movement of contaminated fluid from a solid waste landfill into a portable water aquifier located beneath is an example of underground flow.
ABSTRACT The phenomenon of detection of flow of water in porous media of different porosities with porosity ratio, is similar to the fact that there is deviation in fluid flow in a pair of media of different densities.
ABSTRACT A simple inexpensive chemical route has been identified and used to synthesize cupric oxide nanoparticles suitable for photovoltaic applications. X-ray diffraction analysis showed the synthesized nanoparticles to be a pure cupric oxide phase. The particle size and particle size distribution of the cupric oxide nanoparticles were obtained by transmission electron microscopy (TEM) whereas the crystallite size and crystallite size distribution were obtained by X-ray diffraction peak bro...