Browsing by Author "Adegoke, J. A."

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Analysis of heavy metals concentration in sediments and water samples of selected functional dams in Oyo State, Southwestern Nigeria
(2008) Adegoke, J. A.; Sunmonu, L. A.; Ojeniyi, O. S.
"The quality as well as the quantity of clean water supply is of vital significance to the welfare of mankind particularly in the developing countries. Therefore, knowing the concentration of heavy metals present in Dams can help us to ascertain the health safety of the populace using the water for drinking and domestic purposes. Ten Dams at Oyo State in the Southwestern Nigeria were studied for the heavy metals concentration contained in the sediments and water of the selected Dams. Bottom sediments and water were collected from the selected dams for analysis. Analysis of both the water and sediments to determine the concentration of each heavy metal was evaluated. The result obtained shows that, the concentration of Manganese (Mn) ranges from 14.8 mg/kg to 332.96 mg/kg followed by Zinc (Zn) which ranges between 6.18 mg/kg and 52.53 mg/kg which spread across all locations., Lead (Pb) was not detected in virtually all the locations except in Ilora which has a concentration of 0.87 mg/kg and this may be as a result of the activities of motor mechanics and vulcanizers around the dam. In the water samples, the result showed that the concentration of heavy metals is very low which is far below the limit specified by World Health Organization (WHO). Zn has the highest concentration ranging from 0.049mg/kg to 0.729mg/kg, followed by Mn which has concentration between 0.011mg/kg and 0.344mg/kg. Pb, Cadmium (Cd) and Cobalt (Co) were not detected at all in all the water samples. The variation in the concentrations may be due to geological nature of the ground, solubility, an ion exchange and human activities. "
A case study of the depth of fresh/ Salt water interface using values of freshwater heads in groundwater of variable density
(2012) Adegoke, J. A.; Owoeye, O. I.; Ozebo, V. C.
"Almost two thirds of the world's population lives within 400 km of the ocean shoreline; just over half live within 200 km, an area only taking up 10% of the earth's surface. As the world's population continues to grow at an alarming rate, fresh water supplies are constantly being depleted, bringing with it issues such as saltwater intrusion and increasing the importance of groundwater monitoring, management, and conservation. Constant monitoring of the fresh/salt water interface is necessary for proper management of ground water resources. This work studies the variation in the depth of fresh/salt water interface using different values of freshwater heads extracted from heads in coastal groundwater system near The Hague, Netherlands along sections P-DD. Results showed that high density difference between freshwater and saltwater has little effect on the depth of fresh/saltwater interface."
Characterizing buried metallic objects in porous media from attenuation fluctuations
(Academic Journals Inc, 2013) Akinyemi, O. D.; Adegoke, J. A.; Salam, M. A.; Badmus, B. S.; Awokola, S. O.
"Study of attenuation characteristics of electromagnetic signals passing through porous media is becoming increasing relevant in providing important insights into the physical properties of the medium and objects that are buried therein. Laboratory experiments have been carried out in this work to determine the relationship between Q-factor of the electromagnetic signal passing through buried metals and the porosity of the surrounding sediments. Sediments were obtained from Erinle River in Ilobu, Southwestern Nigeria and Iron, Silver and Copper plates of similar dimensions were buried inside box-filled sediment in succession. Electromagnetic signal was passed through metal, sediments and sediments with buried metals while lissajous figures generated at different frequencies were analyzed to assess the impacts of buried objects. Results showed that Q-factor decreased as the porosity of riverbed sediments increased. Of the metals buried inside the sediments, Iron had the most attenuation effect while Silver plates had the least, except at frequency 400Hz where Copper had the least and at 600Hz where there were some overlaps between Silver and Copper. Q-factor increased, for all metals and at all signals frequencies, up to a maximum value at the porosity of 0.24 and thereafter decreased. Knowledge of Q- factor from attenuated signals is therefore, a useful way to characterize and identify buried materials "
A computation of laminar flow in open channels and its application to sheet erosion
(Devon Science Company, 2011) Adegoke, J. A.; Egbeyale, G. B.
The concerntration of heavy metals in selected clay samples in ekiti state, southwestern Nigeria
(2011) Adegoke, J. A.; Oseni, S. O.; Adegbola, R. B.
"The presence and possible effect of heavy metal (such as cadmium, zinc, lead, e.t.c) concentration in the clay used in pot making were investigated. Clay samples were collected at three locations where they are used mostly in making pots and other kitchen utensils. The concentrations of heavy metals were determined using the Atomic Absorption Spectrometer (AAS). Results indicate that the concentration Cu, Zn, Cr, Pb, As, and Mn falls within the range of the maximum admissible concentration of heavy metals of several countries mostly in Europe. However, the concentration Cadmium and Nickel are relatively higher than the maximum admissible concentration of toxic metals in soil for countries like Denmark and Sweden."
Dependence of attenuation of ionizing radiaion on compression and dimension of geologic material (an application to X-ray shielding)
(2011) Adegoke, J. A.; Olowomofe, O. G.
"Search for alternative materials required for shielding ionizing radiation has being on the increase for some period of time. Lead which is widely used is expensive, therefore researches has to be carried out on other materials. Clay has been suggested but it is not as effective as lead in shielding ionizing radiation. This work therefore studies the compression of clay samples at different pressures and thicknesses, so as to improve its shielding ability in the attenuation of ionizing radiations. The research work was on pure clay material and studied their effectiveness as radiation shielding material. The samples were made in bricks and their linear attenuation coefficients were measured at two different X-ray energies of 60keV, 10 mA and 120 keV, 15 mA. The samples were compressed at a pressure of 875Nm-2, 1750 Nm-2, 2625 Nm-2, 3500 Nm-2, and 4375 Nm-2, for thicknesses of 1.0cm, 1.5cm, 2.0cm, 2.5cm,and 3.0cm. The result obtained shows that as the thicknesses increases, the linear attenuation increases which is in conformity with Lambert beer’s equation. The attenuation coefficient obtained shows increase in value when compared to ordinary clay samples that were irradiated without compression. "
Depending of thermophysical properties of clay on concerntation of some heavy metals
(Duncan Science Compnay, 2011) Adegoke, J. A.; Egbeyale, G. B
"This paper presents the relationship between thermo physical properties (thermal conductivity and thermal diffusivity) and heavy metal concentration of some surface clay from six local governments in Ibadan, Oyo state, Nigeria. An atomic absorption spectrometer (AAS) was used in analyzing 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 that element. A transient measurement technique was wed to determine the thermal conductivity and thermal diffusivity. Thermal conductivity of each sample was compared with the concentration of heavy metals present in the sample. Based on the results obtained from AAS, Manganese has the highest concentration in all the samples. It was followed by Zinc and the least was lead. The values of temperature, time and their respective measured thermal conductivity were highly correlated; with correlation coefficients between 0.9 and 1. "
Determination of transition length in flow through porous sand material
(2009) Adegoke, J. A.; Olowofela, J. A.
A transition length is normally observed when fluid flows through a conduit before laminar flow is accomplished. This work examined a situation whereby porous materials were filled into the conduit and fluid was made to flow through. An attempt was made to determine this transition length for flow of water through riverbed sand of varying porosities filled into a horizontal cylindrical pipe of diameter 0.345 x 102m with piezometric water head, set at 0.06m. The transition length was observed to be constant for the samples considered and it occurred at 0.60m from the point of entrance; nevertheless, values of pressure at this point increases with increase in porosity.
Effects of clay content and porosity on wave velocities in unconsolidated media wing empirical relations
(Nanjing Institute of Geophysical Prospecting, 2004) Olowofela, J. A.; Kamiyole, I. C.; Adegoke, J. A.
"Wave velocities in sandstones are greatly influenced by porosity and clay contents. We formulated new empirical relations for the velocities Vp and Vs in these media which take into account the porosity and clay contents. These relations are Vp=5.57 - 6.47ø - 2.27C1 ø and Vx=3.41 - 4.44ø - 2.23C1 ø, and can be used to compute velocitiesfor various porosities and clay contents. The result compare favourably with those of other works. "
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. "
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. "
Evaluation of heavy metal status of water and soil at Ikogosi warm spring, Ondo State Nigeria
(Department of Geography and Enivironmental Studies and Management, Bahir Dar University, Ethiopia, 2009) Adegoke, J. A.; Agbaje, W. B.; Isaac, O. O.
The concentration levels of selected heavy metals, (Cu, Cd, Zn, As and Cr) were determined in the soil (ug/g) and water (ppm) samples collected at Ikogosi Warm Spring, Ekiti State, Nigeria. After digestion, Atomic Absorption Spectrophotometer (AAS) was employed for the determination. The study area was at Latitude of 7° 35' 38.9'' Longitude of 4° 58' 52.6'' and at average elevation of 479m above mean sea level (msl). The average concentrations (ug/g) of the heavy metals in the soil are Cu (5.29), Cd (1.50), Zn (46.72), As (10.50) and Cr (339.78). The average concentrations (ppm) of the heavy metals in the water are Cu (4.8), Cd (0.15), Zn (4.17), Ar (0.57) and Cr (1.46). The mercury was below detection limit for both soil and water samples. In the overall, the average concentration of chromium is the highest in the soil with concentration of 339.78 ug/g (an average of 84.27%) and cadmium having the lowest with value of 1.50 ug/g (an average of 0.37%). When average concentration of heavy metal in the water was considered, copper had the highest level with concentration of 4.80ppm (an average of 43.01%) and cadmium had the lowest concentration with value of 0.15ppm (an average of 1.43%). Comparison of these results showed that, their mean levels are within the standard values obtained in Nigeria and some developed countries.
Geophysical investigation of effect of Aba-Eku public refuse dump site in Ibadan (South-West Nigeria) on groundwater quality.
(Nigerian Association of Mathematical Physics, 2011) Popoola, O. I.; Adegoke, J. A.; Fakunle, M. A.
Geophysical method was used to investigate the effect of Aba-Eku(N 07° 19.551 E 003° 59.027') public refuse dump site in Ibadan on groundwater quality. "Four vertical electrical sounding (YES) data from the vicinity of the dump site and one YES from the control point were acquired using Schlumberger electrode configuration which were subsequently processed and interpreted bazed on the assess of the iteralive computer model using a finite difference algorithm. The result showed that all the sides of the dump site have low resistivity values (side A, p= 22.3Ὠm; side B, p=31.8 Ὠm; side C, p=38.9Ὠm and side D, p=34.7Ὠm) compared with the resistivity value of the control point (Glory Tower Schools, p=60.6Ὠm). The low resistivity values around the ump site is an indication of groundwater pollution. This was confirmed by the laboratory water sample analysis from the vicinity of the damp site.
Geophysical investigation of foundation condition of a site in Ikere-Ekiti, Ekiti state, south-western Nigeria
(2011) Lateef, T. A.; Adegoke, J. A.
" A geophysical investigation has been performed using Vertical Electrical Sounding (VES) at a site behind Sammy Guest House in Ikere-Ekiti, Ekiti-State to examine the geophysical parameters that can be used to evaluate the structural competence of the shallow section of the subsurface for construction purposes and building development. The schlumberger configuration was used for the data acquisition. The half- currents electrode (AB/2) was used and the quantitative interpretation of the VES involved partial curve matching and 1-D computer iteration. The field data acquired was presented as geoelectric curves and geoelectric section. The interpretation of the field results showed a significant overburden that is up to 8m. The major subsurface layers are the topsoil (mainly clayey sand and sandy clay), lateritic layer and weathered formation. The northern part of the study area shows the lowest resistivity values that suggest high clay content or possible fracture which have impact on the competence and integrity of the soil construction and building development. Therefore, for building development in the study area, the topsoil must be excavated to a reasonable depth at which the soil is adequately competent and choice of foundation material must take into account the characteristics of the clayed material. "
Groundwater contaminated by nitrates- a case study of Ado-Ekiti, Ekiti state, southwestern Nigeria
(David Publishing, 2012) Lateef, T. A.; Adegoke, J. A.
"Nitrate is one of the problematic and wide spread contaminations. Indiscriminate disposition of human and animal wastes in Nigeria especially in urban region, and lack of proper environmental sanitation geared the need for the monitoring of groundwater contamination. This research work monitored the concentration of nitrate and nitrate-nitrogen in portable water from wells in Odo Ado, Ado-Ekiti, Ekiti State, and examined the relationship between this concentration and the well depth as well as its nature (ringing). The results showed that out of 20 water wells sampled, 50% of samples contain high level of nitrate with the highest having concentration of 140 mg/L and least 49 mg/L while the remaining has acceptable concentration ranging between 3.5 mg/L and 35 mg/L with most ringed wells. The mean concentration of nitrates is 48.06 mg/L and the nitrate-nitrogen is 10.85 mg/L. The statistical correlation between the concentrations and depth showed that there is a significant difference between their means at 95% confidence using T-test. Out of ringed wells, five have high concentration and eight have low concentrations while two of the wells (not ringed) fall below the acceptable limit (EPA) which indicates that there are other factors such as closeness to the point source and soil texture which were not considered in this work. Key words: Nitrate, contamination, depth, groundwater, aquifer."
The impact of the variability of ionospheric phase refractive index on radio signals instability
(Academic Journals, 2011) Awe, O. E.; Adegoke, J. A.; Eniafe, B. S.
The ionospheric phase refractive index is a complex function that determines the attenuation and the trajectory of radio signals through the ionosphere. This complex refractive index model has been obtained using the Maxwell's equations, the tensorial conductivity equation, electron collision models, and the geomagnetic field model. The model has been used to study and investigate the phase refractive index on radio wave propagation for high latitude, low latitude and equatorial regions of the global ionosphere, at 1400 h LT, during the periods of high solar activity (Rz = 104.5, year 1970), moderate solar activity (Rz = 68.9, year 1972) and low solar activity (Rz = 12.6, year 1976). Our results showed that ionospheric phase refractive index is not constant, less than unity, increases with increasing propagating radio frequencies and for a particular propagating radio frequency, it increases with decreasing solar activity
Investigation of groundwater development in four areas of Ido local government resistivity method
(2010) Popoola, O. I.; Adegoke, J. A.; Fakunle, M. A
"This study focuses on the use of geo-electrical sounding for groundwater prospecting in four areas namely Ido Motor Park, (N 07° 18' 40.3"", E 003° 50' 29.2"") Elere- Apata '(N 07° 18' 40.3"", E 003° 50' 29.2"") Bakatari (N07° 18'40.3"", E 003'50'29.2'') and Apete Market (N07° 18' 40.3"", E 003°50' 29.2"") in Ido local government area Southwestern Nigeria. Two (2) Vertical electrical soundings (VES) were carried out using Schlumberger configuration at each of the selected area making a total of eight VES in the four selected areas of the local government. The field resistivity data acquired were plotted on bilogarithm paper and preliminary interpretation was carried out using partial curve matching involving two - layer master curves and the appropriate auxiliary chart. The layered models obtained were subjected to computer iteration using WIN RESIST Version 1 .O. The results of the sounding reveal a system of three to four geo-.electric layers of resistivity ranging from 126.7Ὠm to141 8.8Ὠm Deeply weathered material is quite evident within the premises: Groundwater development in the study area would be feasible if the deeply weathered / fractured basement is fully penetrated. "
Laboratory investigation of salt-water intrusion through porous media
(2011) Adegoke, J. A.; Olatunde, I. P.; Faluyi, O. O.
" Flow rate of salt-water and fresh-water through porous media depends on the hydraulic gradient, porosity and hydraulic conductivity of the sand materials and the properties of the fluids such as density and viscosity. This study examined flow rate of salt-water and fresh-water in porous media in a modeled laboratory experiment. Porous materials were filled into the conduit of two arms glass cylindrical tube with valve (control) at the middle. Salt-water and fresh-water were made to flow through the porous materials from the different arms. The volume displacements of salt-water and fresh-water in the two arms glass cylindrical tube filled with riverbed sand of varying porosities were determined when the valve between the two arms was opened with different hydraulic heads of fluids in the tube. Salt-water displaced the fresh-water upward in the set up when hydraulic level of salt-water is greater than hydraulic level of fresh-water. Salt-water also displaced the fresh-water in the set up when the hydraulic level of salt-water is the same as the hydraulic fresh-water. But fresh-water displaced salt-water only when hydraulic level of fresh-water is greater than hydraulic level of salt-water. "
A laboratory study of the effects of porosity and bed tilting on the discharge rate of groundwater
(Springer India, 2005) Olowofela, J. A.; Adegoke, J. A.
The study of movement of underground water helps to predict the extent of flow in as much as we can determine the volume rate among other things. Sand samples from river bed were used as porous media, a laboratory experiment was set up to look at longitudinal dispersion in term of volume of liquid flowing across a unit cross sectional area per unit time in these materials. Water was made to flow through a cylindrical pipe drilled sideways at intervals. Values of pressure were taken at regular interval and using appropriate basic equations, the volume flux rate was determined at various angles of tilt, from which volume rate of flow was also determined. A graph of volume rate of flow against angle of tilt gives the value of volume rate of flow as 1.00 ' 10-10 m3/s irrespective of porosity and permeability of the medium provided that the angle of tilt is 1.42°
Lead adsorption in clay and its application
(EJGE, 2012) Adegoke, J. A.; Babatunde, E. G.
"This work presents the adsorption capacities of some heavy metals in clay soil and its application in medical field. Nitrate of lead solution of different concentrations were prepared (400ppm, 800ppm… 6400ppm). Each concentration of lead nitrate solutions was mixed with a known volume of clay. Slabs of regular dimensions were formed from the residue after it had gone through filtration. Each slab (dried) was irradiated with x-ray radiation at different energies; 40kev, 60kev, 80kev,100kev and 120kev. Linear and mass attenuation of each slab were determined. We did this in order to check shielding ability of the adsorption capacities of heavy metals in clay soil. The research works on clay soil used mainly in building construction and pot making. A PTM UNIDOS electrometer at National Institute of Radiation Protection Research (NIRPR), University of Ibadan, was used to record the counting .A Graph of logarithm of incident intensity versus logarithm of transmitted intensity was plotted to calculate mass attenuation of the slabs at different concentrations. An Atomic Absorption Spectrometer (AAS) was used in analyzing the concentration of heavy metals present in each sample. The results obtained from X-ray Photoelectron Spectroscopy (XPS) show that attenuation coefficient decreases as the radiation energy increases. The linear correlation coefficient between the concentration of heavy metals and attenuation coefficient was approximately 1. "