Physics
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Item The effects of porosity and angels of inclination on the deflection of fluid flow in porous media(Medwell Journals, 2009) Popoola, O. I.; Adegoke, J. A.; Alabi, O. O."The movement of contaminated fluid from a solid waste landfill into a portable water aquifer located beneath is an example of unwanted underground flow. With the problem of limited portion of land available for building construction in the cities, coupled with the rise in price of good and accessible land, there is a need for quick and urgent solutions to environmental pollution that may be resulted from this problem. In this research, a laboratory setup consisting of a big transparent cylindrical pipe 108.5cm long with radius 2.23cm was used as inlet pipe and five small equal transparent cylindrical pipes with radii 0.03cm were used as outlets, which were joined to the circular plastic plate on the top of the inlet pipe at different angles ranged from 00 to 900 from a normal point. The inlet pipe and outlets pipes were filled with samples of soil of different porosities and titled at different angles of inclination. The volume of water discharged was measured directly with measuring cylinder from the set-up in each case. The volumetric flow rate and volume flux were computed from the values of volume discharged. These were done in order to determine how the arrangement of porous material of different porosities with a particular angle of inclination can influence the deflection of fluid flow from its linear direction. This is sequel to its practical applications in designing a construction with a cross-section of soils in deflecting contaminated fluid from septic tank to different directions from the source of water within the same small portion of land. It was observed that angle of inclination does not have a significant effect on the deflection of fluid but volume flux increases with increasing angle of inclination. Also, the greater the difference in the porosity of the cross-section of the media in which the fluid is flowing the greater the volume flux. However, the most suitable arrangement of cross-section of soils for deflection of fluid at higher angle from normal is when it flows through a medium of low porosity to that of higher porosity. "Item The effects of porosity and angle of inclination on the deflection of fluid flow in porous media(Bachudo Science Ltd, 2009) Popoola, O. I.; Adegoke, J. A.; Alabi, O. O."The movement of contaminated fluid from a solid waste landfill into a portable water aquifer located beneath is an example of unwanted underground flow with the problem of limited portion of land available for building construction in the cities, coupled with the rise in price of good and accessible land, there is a need for quick and urgent solutions to environmental pollution that may be resulted from this problem. In this research, a laboratory setup consisting of a big transparent cylindrical pipe 108 5cm long with radius 2 23cm was used as inlet pipe and five small equal transparent cylindrical pipes with radii 0.03cm were used as outlets, which were joined to the circular plastic plate on the top of the inlet pipe at different angles ranged from 0° to 90° from a normal point. The inlet pipe and outlets pipes were filled with samples of soil of different porosities and titled at different angles of inclination. The volume of water discharged was measured directly with measuring cylinder from the set-up in each case. The volumetric flow rate and volume flux were computed from the values of volume discharged. These were done in order to determine how the arrangement of porous material of different porosities with a particular angle of inclination can influence the deflection of fluid flow from its linear direction. This is sequel to its practical applications in designing a construction with a cross-section of soils in deflecting contaminated fluid from septic tank to different directions from the source of water within the same small portion of land. It was observed that angle of inclination does not have a significant effect on the deflection of fluid but volume flux increases with increasing angle of inclination. Also, the greater the difference in the porosity of the cross-section of the media in which the fluid is flowing the greater the volume flux However, the most suitable arrangement of cross-section of soils for deflection of fluid at higher angle from normal is when it flows through a medium of low porosity to that of higher porosity. "Item Modification of fluid flow equation in saturated porous media(Bachudo Science Ltd, 2009) Alabi, O. O.; Popoola, O. I.; Adegoke, J. A.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 experimental data were considered. A general equation for both laminar and non-laminar or turbulent fluid flow in porous media at any hydraulic gradient is proposed, including the boundary conditions.Item Radiogenic heat production distribution of soil samples from Idi Omo, Akinyele LGA, Oyo State, Nigeria(Creative Commons Attribution, 2009) Adegoke, J. A.; Layade, G. O.; Popoola, O. I.The NaI(TI) gamma-ray spectrometer was employed to determine the concentration of naturally occurring Potassium(K-40). Uraniurn (U-238) and Thorium (Th-232) vis-à-vis the radiogenic heat production in soil samples from Idi-Omo farmland area of Akinyele, Local Government area o f Oyo state. The farmland which is at Latitude 07° 30’ 26.3" and Longitude 003° 57' 21.9" covers an area of about 80,000 square metre, and is at an average elevation of 240m above mean sea level (msl). The samples were pulverized, sealed and activities of the radiogenic isotopes in them were measured for an accumulating period of 7 hours (25200s). The elemental concentrations were determined from the gamma ray spectra. The radiogenic heat determined from activity concentrations on samples from the locality for 40k has on the average 92.86±0.02p W/Kg, while 238U has 251.26±0.61pW /Kg and 232Th has 77.210±0.03pW/Kg. The mean radiogenic heat calculated from the three radionuclides for the whole area under study is 421.3.3±0.66pW/Kg. 238U contributes 60% to the total heat production, 40K contributes 22% and 232Th contributes 18%. This makes Uranium to be the highest contributor to the total heat production in the area. However observed that the radiogenic heat production distribution in the area is low.Item Study of permeability of saturated homogeneous and heterogeneous porous media(Duncan Science Company, 2008) Popoola, O. I.; Adegoke, J. A.; Alabi, O. O.Many practical seepage and drainage problems can be studied by constructing flow nets for section with a single permeability, however, many natural soil deposits are more or less stratified, often with horizontal bedding that make horizontal permeabilities much greater than the vertical. Three different types of heterogeneous media from five soil sample of different porosities were considered: with constant-head permeameter to determine the saturated hydraulic conductivity for each. The result shows that least permeable medium dominates in the permeability of heterogeneous medium than layered heterogenous medium. However, fluid flow in homogeneous porous media is generally faster than that of heterogeneous medium of similar geometry and grains packing. Therefore, the effect of least permeable unit in heterogeneous medium must be considered in selecting a proper filter for seepage control.Item Modification of Darcy's law for turbulent flow in saturated porous media(Medwell, 2007) Popoola, O. I.; Adegoke, J. A; Alabi, O."Darcy's law is an essential equation in determining the permeability of porous media which is vital tool in seepage and drainage control in soils. However, whenever the aggregate sizes of the porous media and hydraulic gradient are large, the flow in drains will be semi-turbulent to turbulent. This research aims at modifying the true Darcy's permeability determined under small hydraulic gradients that ensure laminar or nearly laminar flow to allow for reduced efficiency caused by turbulence at greater hydraulic gradient and provide a relation between the maximum gradient for laminar flow and porosity of the porous media. A modeled experiment was set up using sand samples of different porosities from riverbed as porous media, which were packed in a vertical transparent cylinder tube of diameter 1.85x102m and relative permeabilities were determined for gradient ranging from 1.15-15.00. The result of the experiment shows that relative permeability increases with increasing porosity but decreases with increasing gradient. The maximum (or limiting) hydraulic gradient for laminar flow decreases with increasing porosity. Also, the vertical fluid flow in any porous medium is laminar or nearly laminar as much as hydraulic gradient is less than or equal to 1.04. "