Scholarly works
Permanent URI for this collectionhttps://repository.ui.edu.ng/handle/123456789/420
Browse
75 results
Search Results
Item Groundwater abstraction: a model for saltwater intrusion of coastal fresh water(2017) Adebo, B.; Adetoyinbo, A.The knowledge of salinity level and intrusion of saltwater into freshwater aquifer is necessary for groundwater monitoring and prediction in the coastal areas. In this work, an advection-dispersion saltwater intrusion model is used to study and simulate saltwater intrusion in a typical coastal aquifer. The aquifer portion was divided into grid with elements and nodes. Map of the study area indicating well locations was overlain on the grid system such that these locations coincide with the nodes. Chlorides at these wells were considered as initial nodal salinities. Results showed a highest and lowest increase in simulated chloride of 37.89 mg/L and 0.8 mg/L respectively. It also revealed that the chloride concentration of most of the considered well may climb unacceptable level in the next few years, if the current abstraction rate continues unabatedItem Determination of temperature profile of the lithosphere between zero and 150 km penetration at Itagunmodi, Nigeria(AJOL, 2019-06) Adetoyinbo, A. A.; Bello, A. K.In this work the temperature profile for the lithosphere was determined using data from radiogenic heat source and heat from other sources from 0 to 150 km depth was determined using a suitable mathematical expression. The temperature at the base of the lithosphere was given between 1200°C to 1600°C. The Fourier’s law was applied and the results showed that the profile range from 27.0°C to 1483.3°C. These results compared favourably well with existing literature values.Item Assessment of building failure within and around quarries(2019-07) Adetoyinbo, A. A.The substructures of various engineering structures that were erected on the earth are being were been supported by the soil. Hence, the nature of the soil supporting these structures becomes an important issue. Quarry blasting peak particle velocity (QBPPV) is not sufficient to ascertain the causes of foundation failure, therefore, the physical parameters governing the competency of the soil supporting engineering structures need to be determine. This work investigated the possible causes of foundation failure of buildings within the vicinity of quarries. The investigation was done by carrying out Vertical Electrical Sounding (VES) and Radial Vertical Electrical Sounding (RVES) using Campus omega terrameter. The results show that buildings found within this area have shallow foundation and their foundations founded on sandy clay which can still support foundation The values of the degree of fracturing was found not to exceed 1.53 in this region which was not the case with the previous radial vertical electrical soundings, 1.94 was calculated as the highest degree of fracturing for RVES 1 while 1.83 was calculated for RVES 2. In all the RVES, degree of fracturing ranges between 1.02 to 1.94.Item A four-point electrical resistivity method for detecting wood decay and hollows in living trees(Springer, 2019-05) Soge, A. O.; Popoola, O. I.; Adetoyinbo, A. A.An accurate method of detecting wood decay and hollows or cavities in living trees is useful for risk assessment and maintenance of both forest and urban trees. This study presents the implementation of the four-point electrical resistivity method for the early detection of the presence, location and extent of wood decay and hollows in living acacia trees (Senna cilata L.). Electrical resistivity measurement of randomly selected living acacia trees and a freshly-cut acacia tree with decay and hollows were taken to obtain electrical resistivity profiles for sound, decayed and hollowed trees. A laboratory experiment was set up to replicate the resistivity profiles. Wood decay and hollows were replicated at different depths in the laboratory prototype using good electrical conductors and insulators respectively. Resistivity profiles for the sound, decayed and hollowed trees were obtained from the experimental and field results. The resistivity profiles were applied to detect decay and hollows of similar dimensions in living trees through resistivity curve matching. The electrical resistivity of the decayed acacia tree was markedly lowered by an average factor of 5 compared to that of the sound acacia tree. Likewise, the electrical resistivity of the hollowed acacia tree was noticeably greater than that of the sound acacia tree by an average factor of 4. Wood decay and hollows modelled into the laboratory prototype were detected with relatively lower and higher resistivity anomalies respectively. The method indicated that 80% of the randomly selected living trees were sound, healthy trees, whilst 20% had decay and hollow at the time of measurements. This method is suitable for early detection of decay and hollows in hardwood trees.Item Detection of decay and hollows in living almond trees (terminalia catappa L. roxb.) using electrical resistivity method(Springer, 2018-10) Soge, A.; Popoola, O.; Adetoyinbo, A.A precise and cost-efficient diagnostic technique for detecting decay and other structural defects in living trees is indispensable for the risk assessment and conservation of urban and forest trees. A study was carried out to detect the location and extent of decay and hollows (or cavities) in almond trees (Terminalia catappa L. Roxb.) using the four-point electrical resistivity method. Electrical resistivity measurements (ERm) of randomly selected living almond trees were taken using an earth resistivity meter, four probes and a modified form of Schlumberger electrode configuration. The ERm were used to obtain resistivity profiles (RP) of the trees. The RP of freshly cut healthy, decayed and hollowed trees were also obtained. A laboratory experiment was set up to replicate the RP of healthy, decayed and hollowed trees. Wood decay and cavities in trees were detected through RP matching. In comparison to healthy trees, wood decay and cavities in tree stems were detected with relatively sharp decrease and increase in electrical resistivity values, respectively. The extent of the resistivity anomalies corresponds to the extent of wood decay and cavities in trees. This method is applicable to early detection of decay and cavities in hardwood trees.Item Gravity anomaly and basis symmetric matrix Interpretation for residuals(2018) Adetoyinbo, A. A.; Ewumi, T. O.Gravity method has tremendously pervaded the field of geophysical exploration and thus extensively discussed and vividly illustrated in this work. The basis for symmetric matrix data gravity interpretation was earlier proposed, then extended to residuals and interpretation. A symmetric matrix representation is discussed further to residuals, spectral, interpretation, and optimistically forms a veritable tool for gravity data interpretation. The fundamental law of gravitational attraction is essential in delineating gravity data interpretation and the gravity effect or anomaly representation is evidently expressed by a finite difference matrix in the discussion. A computational extension can be done based on the symmetric matrix representation with available gravity data and a vivid illustration for anomaly and residual computation has been madeItem Peak particlevelocitydataacquisitionfor monitoring blast induced earth quakes in quarry sites(Elsevier Inc., 2018) Hammed, O. S.; Popoola, O. I.; Adetoyinbo, A. A.; Awoyemi, M. O.; Adagunodo, T. A.; Olubosede, O.; Bello, A. K.The peak particle velocity datasets recorded during quarry blasts in the neighborhood villages and towns in Ibadan and Abeokuta were processed and analyzed in order to recommend a safe blast design for each of the quarries. The minimum peak particle velo- city of 48.27 mm/s was recorded near the foundation of the nearest residence at the shot to monitored distance of 500m. The ten- dency of ground vibration emanating from the quarry sites to cause damage to the structures in the nearby dwelling areas is very high. The peak particle velocity datasets recorded were not within the safe limit. Therefore, the peak particle velocity that will not exceed 35 mm/s is recommended for a safe blast designItem Employing DC resistivity method for hydrogeological analysis of Zuma II, a VES approach(2017) Dikedi, P. N.; Sule, A. U.; Adetoyinbo, A. A.This research work employs the DC Resistivity method for Hydrogeological analysis in Veritas University, Zuma II, Bwari Area Council, Abuja, FCT, Nigeria. The work attempts to tackle the immense water shortage crisis within the University, this work also, attempts to provide access to stratigraphic information and to assist groundwater development for the region. Schlumberger array and electrical sounding technique are adopted for subsurface delineation. Eleven resistivity profile graphs generated from tabled data are presented by employing the Winresist software and Microsoft excel. A The outcome of this investigation revealed four spots with good potentials for ground water; these points are located within the fifth and third layers on 9.28498°N, 7.41875°E (VES 1); 9.28515°N, 7.41789°E (VES 5); 9.28437°N, 7.41793°E (VES 8); 9.28394°N, 7.41792°E (VES10). Furthermore, the outcome of this work revealed the lithology of the region investigated. Five distinct layers of varying thicknesses and depths were displayed: Top soil, Clay, Sandy clay, Fractured and Basement Rocks. From the collated readings, the derived average thicknesses of topsoil, sandy clay and clay are 0.8 m, 10.2 m and 7.06 m respectively.Item Estimation of outflow discharge from an ungauged river: case study of Awara in Ondo State Southwestern, Nigeria(2017-10) Alabi, O. O.; Sedara, S. O.; Adetoyinbo, A. A.; Akinwande, D. D.Flooding has become the annual experience of Nigerian cities especially in the southwestern states of country, precisely Ondo state. This study uses Muskingum Cunge method river routing techniques to compute outflow discharge and to determine hydrographs of inflow and outflow pattern of Awara river Ikare Akoko, North east LGA in Ondo State, Southwestern of Nigeria. The Muskingum Cunge method of flood routine reflects the interrelationship existing between the inflow and outflow of river. The average monthly inflow discharge for twenty years was worked on using Muskingum Cunge method of flood routine. Observation from the hydrograph shows th'at inflow peak occurs in the month of April, while the outflow in the same month is very low. This implies that the month of April is a critical month that needs a special attention and there is a need for channelization of this river before the month of April every year, in order to prevent occurrence of flooding whenever there is heavy rainfall.Item Numerical modeling to study the effect of small bottom irregularities on steady flow in homogeneous ocean(2018-07) Bello, A. K.; Ogunseye, T. T.; Adetoyinbo, A. A.; Ibrahim, A. H.The numerical modeling of topographic waves is based on the continuity and momentum equations. The solutions of these equations for the vertical and horizontal velocities and surface elevation of the oceans were obtained through a FORTRAN- program that was run using different values of bottom slope (a), coefficient of bottom friction (r) at different intervals (n). Slopes of the plots of horizontal, vertical velocities and surface elevation of the ocean for flat bottom ocean and fixed values of bottom friction were obtained. Similarly, slopes of the plots of resultant velocity against surface elevation and surface elevation versus horizontal and vertical velocity were also obtained. The resultant velocity (c) against the surface elevation η of the ocean produced negative slopes. The low value of slopes is an indication that the ocean waves move slowly and steadily.