Doctor of Philosophy (Ph.D.) Theses and Dissertations

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Open Access
A mathematical model for explosions with chain branching and chain breaking kinetics
(Department of Mathematical Obafemi Awolowo University, 1989) Samuel Segun OKOYA
A mathematical model for explosions with chain branching and chain breaking kinetics is presented in this thesis to give further insight into the theory of combustion reactions under physically reasonable assumptions.
Open Access
A study of heavy metal speciation and free fatty acid levels of the Obafemi Awolowo University's sewage treatment oxidation pond and its receiving stream
(Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria., 2015) Obisanya, Joshua Funminiyi
Levels of different metal species and free fatty acids (FFAs) of a sewage treatment oxidation pond (STOP) of the Obafemi Awolowo University and its receiving stream were assessed. This was with a view to appraising the effectiveness of the pond in removing heavy metals, establishing the quality of water at downstream, and the potential toxicity of water and sediment of the study area.
Open Access
An evaluation of the Nigerian innovation system and technoloical capability building in the manufacturing sector.
(Department of Technology Management Obafemi Awolowo University, 2005) OKE, Joseph Sunday
This study evaluated the knowledge generation and utilization performance and the operational environment of the Nigerian innovation system with the aim of establishing the level of technological capability building in the manufacturing sector. In conclusion, the Nigerian innovation system was generally too weak to support sufficient technological capability building in the manufacturing sector due to factors such as low spending on R&D, low level of S&T human resources , poor state of research facilities and poor linkage between academic /research institution and firms.
Open Access
Analysis of batch arrivals with multiple service for unbalanced queueing systems
(Department of Mathematics, Faculty of Science ,Obafemi Awolowo University ,Ile -Ife, 0222) Babalola, Ajiboye Reginald
This study designed a prototype of an unbalanced Combined Input Crosspoint Queued (CICQ) queueing system, obtained the possible states at the moment just before a departure for some specific gridpoints and provided the system solution in terms of those grid points and analysed the performanceof the proposed system. These were with a view to establishing relevant flow balance equations and analysing the traffic at various levels of interactions of contending units for congestion, complexity and grid points. Considered is a two-stream toll gate system modified from the CICQ switch system of homogeneous and heterogeneous packets. The Markov Modulated Poisson Process (MMPP) were superimposed at the input port to obtain the defined states at (u, v,w)k for epoch or moments just after a departure of type k which identified admissible states and their transition probability matrix was obtained using various combinatorial reasonings. The work thereafter, formulated governing equations from relevant flow balance equations, which were of the form ΠP = Π and solved them for stationary probability vectors. Subsequently, the work obtained the mean recurrence times for each state and mean first passage times from one state to the other. Highlighted in particular, were the situations of the extreme cases of heavy traffic (HT) with 27 possible states when the system was saturated with contending units and two cases of restricted light traffic. The restricted traffic was such that traffic (u, v,w) at the moment just before a departure, was guided by the conditions u ≤ 2n, v ≤ 2n, w ≤ n and v+w ≤ 2n where u, v,w and n were integers connoting number of different units in the queues. The light traffic case I (LTS I) connoted n = 1 with 17 admissible states and the light traffic case II (LTS II) connoted n = 2 with 86 admissible states for a 27 grid point system. For a combination of service times τ1, τ2, τ3, the resulting combination were evaluated for cohersion, stability and efficiency using measures of the minimum mean first passage times Tmin(ijk), Concentration Index (C) and the Euclidean Distance Measure (dI/II ). The result from the mean first passage time for all three systems provided a measure of the sensitivity for the stationary probability vectors as defined in their respective underlying states. The mean first passage times tijk was found to be a stochastic process of its own with respect to each of the models, matrices and values, in correspondence to the gridpoints as defined by the parameters of the light traffic case I (LTSI), light traffic case II (LTSII) and the heavy traffic situations (HTS). Thetendency to concentrate (or dominate) on any state is lower for the heavy traffic, though steady, but cannot be sustained when compared with the light traffic cases. This tendency for concentration was found to be closer for both light traffic cases but the LTS II case was uniformly less concentrated than that of the LTS I case. The order, therefore, of the concentration Index C for the three systems is HTS < LTS II < LTS I by considering all the grid points. The value of the concentration index C for the heavy traffic ranges from 0.047 to 0.05, that of the LTS II ranges from 0.07 to 0.35 while the one for LTS I ranges from 0.08 to 0.37. The minimum Euclidean distance (dI/II ) compared to the restrictive light traffic cases, in relation to matching similar states, is wide. The width is in the multiple of 104. The least active destination states service type III has the lowest value of 4.34, while the most active destination state for service type III has a value of 6.42. It was noted that the minimum Euclidean distance dI/II appeared progressive as the destination states increases. However, the order of spryness for the three types of service is service type I > service type II > service type III. The study concluded that the Combined Input Crosspoint Queued switch model is able to predict relative performances of traffic systems based on the objective matrix for different levels of complexity and congestion.
Open Access
Antibiotic susceptibility and molecular analysis of staphylicoccus aureus from nasal samples of west african dwarf goats (Capra hircus) in Osun State, Nigeria.
(Department of Microbiology, Faculty of Sciences, Obafemi Awolowo University., 2022) TAIWO, Fadekemi Funmilayo
This study isolated and identified Staphylococcus aureus from the anterior nares of West African Dwarf (WAD) goat in Osun State, Nigeria, determined the antibiotic susceptibility pattern of S. aureus isolates and identified methicillin-resistant S. aureus (MRSA) isolates and Panton Valentine Leukocidin gene. It also investigated the population structure of S. aureus from the nasal samples of the WAD goats. These were with a view to providing information on the prevalence, antibiotic susceptibility pattern, and clonal nature of S. aureus from the nasal samples of WAD goats.
Open Access
Assessment of ecosystem services of Ikogosi warm spring, Ikogosi and Olumirin waterfall, Erin- Ijesa, Southwest, Nigeria.
(Department of Ecology and Enivronmental studies, Faculty of science,Obafemi Awolowo University., 2023) Olusola, Johnson Adedeji
This study profiled the ecosystem services offered by Ikogosi Warm Spring and Olumirin Waterfall, valued the ecosystem services and benefits offered by Ikogosi Warm Spring and Olumirin Waterfall and compared ecosystem services offered between and within the study areas. The study also developed support tools for the management and sustenance of Ikogosi Warm Spring and Olumirin Waterfall. These were with a view to providing a database on the services and benefits offered by these ecosystems and give information on the drivers of ecosystem degradation that have been eroding these values The study was conducted in two phases: field survey and laboratory investigation. Soil and water samples were collected using standard methods to determine their physicochemical parameters. Ecosystem services were evaluated using the carbon tax and industrial oxygen price methods for carbon sequestration and oxygen regulatory services. The market valuation method was used to determine water provisioning services. Travel cost methods were used to estimate cultural benefits. The total ecosystem services of the study areas in monetary terms were calculated by adding carbon sequestration and oxygen potential, water storage capacity, water purification, nutrient cycling, erosion prevention, water consumption, and recreational values. The ecosystem service values of the two sites were then compared. A participatory framework approach was used to develop support tools for managing and sustaining resources of the study areas. Pearson correlation was used to find relationship between the variables while qualitative data was analysed using a thematic approach. The study identified four ecosystem services in the study areas. The total ecosystem services estimated in 2022 was US$132.19 million. Ikogosi Warm Spring contributedUS$ 78.37 million, while the contribution of Olumirin Waterfall was US$ 53.82 million. The contributions of individual ecosystem services at Ikogosi Warm Spring were carbon sequestration (43.8%) >water regulation (29.93%)> water purification (15.96%) > oxygen potential (6.93%), >nutrient recycling (3.23%) > erosion prevention (0.09%). For Olumirin waterfall, the level of contributions of individual ecosystem services was carbon sequestration (39.94%) >water regulation (39.01%) >oxygen potential (13.98%) >water purification (2.75%) > erosion prevention (0.11%). Soil chemical characteristics of the study areas were total nitrogen 8.40 g/kg (Ikogosi Warm Spring), 7.00 g/kg (Olumirin Waterfalls); organic matter 58.00 g/kg (Ikogosi Warm Spring), 26.00 g/kg (Olumirin Waterfalls); available phosphorus 0.80 mg/kg (Ikogosi Warm Spring) and 0.54 m/kg (Olumirin Waterfalls). The water alkalinity was 0.15 mg /l (Ikogosi Warm Spring), 2.40 mg/l (Olumirin Waterfalls); total dissolved solids 0.03 mg/l (Ikogosi Warm Spring), 171.60 mg /l (Olumirin Waterfalls); total hardness 1.13 mg/l (Ikogosi Warm Spring), 0.95 mg/l (Olumirin Waterfalls); turbidity 10.81 (NTU) (Ikogosi Warm Spring), 0.80 NTU (Olumirin Waterfalls) and electrical conductivity 12.06 (μS/cm) (Ikogosi Warm Spring), 1.10 (μS/cm) (Olumirin Waterfalls), Ca2+ (3.44) (mg/l) (Ikogosi Warm Spring), 0.10 (mg/l) (Olumirin Waterfalls); Mg2+ (1.23) (mg/l) (Ikogosi Warm Spring), 0.25 (mg/l) (Olumirin Waterfalls) and dissolved oxygen, 0.25 (mg/l) (Ikogosi Warm Spring), 0.05 (mg/l) (Olumirin Waterfalls) . All the water samples results were below the permissible limits. Focus Group Discussion (FGD) and in-depth interviews from the study showed the negligence of local communities in the sustenance and management of tourist destinations. This study concluded that land use and deforestation were the drivers of ecosystem degradation in the study areas.
Open Access
Assessment of vehicular emission contributions to ambient air quality along high and low density traffic routes in Lagos and Ile-Ife, southwestern Nigeria.
(Department of Chemistry, Faculty of Science. Obafemi Awolowo University., 2021) JOSHUA, Oluwasesan Hezekiah
The study characterized air emissions from vehicles in Lagos and Ile-Ife, determined theground-level concentrations of associated pollutants along with the ambient air quality levels of selected air pollutants and evaluated the vehicular emissions using the results obtained above. These were with a view to assessing the vehicular emission contributions to ambient air quality along low- and high-density routes in Ile-Ife and Lagos. Four sampling points were established during dry and wet season periods over an averaging period of 24-hour, while traffic count, meteorology, and ambient measurements were carried out simultaneously at each of the sampling points. The vehicle emission measurement which is one of the inputs for predicting ground level concentrations using the BREEZE ROAD Model was carried out using Infra-Red gas analysers for CO, NO2, and SO2 concentrations and handheld aerosol real-time particulate matter (PM2.5) sampler for PM2.5 concentration. Ambient PM2.5 concentrations were measured using Air metric particulate matter sampler, while ambient gaseous concentrations of CO, NO2, SO2, O3, and volatile organic compounds (VOC) were measured using CO data logger, Ogawa sampler, and 3 M air monitor badge. The samples collected using the Ogawa sampler and 3 M air monitor badge were analysed using Gas Chromatography Flame Ionization Detector. The measured ambient mean PM2.5 concentration in Lagos was 152.58± 61.65 µg/m3 while that of Ile-Ife was 93.13±2.24 µg/m3. The measured concentrations of NO2 in Lagos ranged from 21.98 to 64.95 µg/m3and that for Ile-Ife ranged from 10.00 to 55.04 µg/m3. Sulphur dioxide concentration ranged from 20.56 to 58.09 µg/m3 in Lagos and 16.35 to 60.69 µg/m3 in Ile Ife. Carbon monoxide concentrations in Ile-Ife sampling points ranged from 1,030.68 to 3,000.42 µg/m3 while that of Lagos sampling points ranged from 1,030.68 to 3,664.64 µg/m3.Comparative high average level (40.02± 8.5 µg/m3) of VOC was recorded in Lagos than Ile-Ife with an average value of 17.33± 5.46 µg/m3. However, all ambient pollutant values were below Federal Ministry of Environment (FMEnv) and World Health Organization (WHO) limits except PM2.5 and SO2. The predicted mean ground level vehicular concentrations of PM2.5, NO2, SO2, and CO for Lagos were 117.00 ± 25.46, 33.87 ± 5.32, 16.78 ± 13 and 1885.7 ± 565.69 µg/m3respectively while that of Ile-Ife were 86.50 ± 3.54, 13.17 ± 7.98, 15.61 ± 10.97 and 1028.60 ± 969.73 µg/m3respectively. Generally, the average percentile contribution of major vehicle criteria pollutants on the airshed along low and high-density traffic routes were 31 and 42% respectively. The study concluded that the pollutant concentration values obtained, apart from those of PM2.5 and SO2 which were below FMEnv and WHO limits, could cause adverse health by those having regular impacts of the parameters investigated.
Open Access
Bioaccumulation and oxidative stress impact of toxic heavy metals and polycyclic aromatic hydrocarbons on selected mosses in Nigeria
(Department of Botany, Faculty of Science, Obafemi Awolowo University., 2023) Olasoji, Kehide Olayemi
This study investigated the bioaccumulation of heavy metals and polycyclic aromatic hydrocarbons in Philonotis hastata (Duby) Wijk & Margad and Barbula lambarenensis P. de la Varde, and also determined the impact of oxidative stress on chlorophyll content and anatomical features of the mosses. These were with a view to providing detailed information on the bioaccumulation potential of the selected mosses as well as the antioxidant response of these mosses to oxidative stress. The moss species were collected in industrial areas in Ile-Ife, Ibadan and Ikeja while the control samples were collected at Obafemi Awolowo University, Ile-Ife. The concentrations of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in moss samples were determined using standard method. Estimation of chlorophyll content (chlorophyll a, chlorophyll b and total chlorophyll) were determined using standard procedure. Stress biomarkers (hydrogen peroxide (H2O2) and proline contents), non enzymatic antioxidant activity (ascorbate, total glutathione, lipid peroxidation and carotenoids) and enzymatic antioxidant activity (superoxide dismutase, catalase and ascorbate peroxidase) were determined following standard procedures. General anatomical features of the stem and leaves of the mosses were studied and photomicrographs of the slides were taken. Data were analyzed using one-way Analysis of Variance (ANOVA) and Duncan Multiple Range Test (DMRT) were used for separation of mean using SAS software, 2001. The concentrations of heavy metals in moss samples in the study locations ranged from: Cu (1.200 – 2.330 µg/g), Zn (0.855 – 1.370 µg/g), Fe (0.525 – 1.050 µg/g), Mn (0.027 – 0.052 µg/g), Cr (0.016 – 0.057 µg/g), Cd (0.018 – 0.045 µg/g), Pb (0.007 – 0.020 µg/g), As (0.010 – 0.018 µg/g). The results revealed that the heavy metal concentrations in the studied moss samples followed the trend: Cu>Zn>Fe>Mn>Cr>Cd>Pb>As. The study showed that copper, zinc and iron were the most accumulated heavy metals while lead and arsenic were the least accumulated heavy metals in all the sampling locations. Moss samples from control sites have the lowest concentration of metals in all the sampling locations. There is significant difference in the accumulation of heavy metals in the mosses with respect to the different locations in the study area. The concentrations of 19 PAHs varied from 0.02 to 3.81 mg/L in P. hastata and from 0.02 to 5.92 mg/L in B. lambarenensis in all the locations. The PAHs were not detected in the moss samples from control sites. Naphthalene and 3-methylcholanthrene were detected in all the study areas except for control sites. There was a significant decrease in chlorophyll a, chlorophyll b and total chlorophyll contents of the selected mosses when compared to chlorophyll contents of mosses from control sites. The selected mosses exhibited significant variations in the antioxidant response to oxidative stress in polluted sites and control sites. The anatomical studies of the stem and leaves of the selected mosses showed there is no feasible effect of pollutants bioaccumulation on micromorphological features of the moss species obtained from polluted sites when compared to moss species from the control sites. The study concluded that accumulation of heavy metals and polycyclic aromatic hydrocarbons in the selected mosses from industrial areas induces oxidative stress and causes reduction in their chlorophyll contents. The antioxidant response of these mosses indicated that the selected moss species were tolerant to oxidative stress.
Open Access
Bioaccumulation and Oxidatives stress impact of toxic heavy metala and polycyclic aromatic hydrocarbons on selected mosses in Nigeria
(Department of Botany, Faculty of Science, Obafemi Awolowo University., 2023) OLASOJI Kehinde Olayemi
This study investigated the bioaccumulation of heavy metals and polycyclic aromatic hydrocarbons in Philonotis hastata (Duby) Wijk & Margad and Barbula lambarenensis P. de la Varde, and also determined the impact of oxidative stress on chlorophyll content and anatomical features of the mosses. These were with a view to providing detailed information on the bioaccumulation potential of the selected mosses as well as the antioxidant response of these mosses to oxidative stress. The moss species were collected in industrial areas in Ile-Ife, Ibadan and Ikeja while the control samples were collected at Obafemi Awolowo University, Ile-Ife. The concentrations of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in moss samples were determined using standard method. Estimation of chlorophyll content (chlorophyll a, chlorophyll b and total chlorophyll) were determined using standard procedure. Stress biomarkers (hydrogen peroxide (H2O2) and proline contents), nonenzymatic antioxidant activity (ascorbate, total glutathione, lipid peroxidation and carotenoids) and enzymatic antioxidant activity (superoxide dismutase, catalase and ascorbate peroxidase) were determined following standard procedures. General anatomical features of the stem and leaves of the mosses were studied and photomicrographs of the slides were taken. Data were analyzed using one-way Analysis of Variance (ANOVA) and Duncan Multiple Range Test (DMRT) were used for separation of mean using SAS software, 2001. The concentrations of heavy metals in moss samples in the study locations ranged from: Cu (1.200 – 2.330 μg/g), Zn (0.855 – 1.370 μg/g), Fe (0.525 – 1.050 μg/g), Mn (0.027 – 0.052 μg/g), Cr (0.016 – 0.057 μg/g), Cd (0.018 – 0.045 μg/g), Pb (0.007 – 0.020μg/g), As (0.010 – 0.018 μg/g). The results revealed that the heavy metal concentrations in the studied moss samples followed the trend: Cu>Zn>Fe>Mn>Cr>Cd>Pb>As. The study showed that copper, zinc and iron were the most accumulated heavy metals while lead and arsenic were the least accumulated heavy metals in all the sampling locations. Moss samples from control sites have the lowest concentration of metals in all the sampling locations. There is significant difference in the accumulation of heavy metals in the mosses with respect to the different locations in the study area. The concentrations of 19 PAHs varied from 0.02 to 3.81 mg/L in P. hastata and from 0.02 to 5.92 mg/L in B. lambarenensis in all the locations. The PAHs were not detected in the moss samples from control sites. Naphthalene and 3-methylcholanthrene were detected in all the study areas except for control sites. There was a significant decrease in chlorophyll a, chlorophyll b and total chlorophyll contents of the selected mosses when compared to chlorophyll contents of mosses from control sites. The selected mosses exhibited significant variations in the antioxidant response to oxidative stress in polluted sites and control sites. The anatomical studies of the stem and leaves of the selected mosses showed there is no feasible effect of pollutants bioaccumulation on micromorphological features of the moss species obtained from polluted sites when compared to moss species from the control sites. The study concluded that accumulation of heavy metals and polycyclic aromatic hydrocarbons in the selected mosses from industrial areas induces oxidative stress and causes reduction in their chlorophyll contents. The antioxidant response of these mosses indicated that the selected moss species were tolerant to oxidative stress.
Open Access
Capability development in adopting active technology transfer strategy in Nigeria Industries.
(Department of Technology Management, Falculty of Technology, Obafemi Awolowo University., 1998) Ephraim Chukwuma OKEJIRI
The main technology acquisition strategy of most developing countries including Nigerian is based on the concept of technology transfer which emphasizes importation of production technology. This development strategy which emerged post second world war era had roots in the revolutionary theory of social change.
Open Access
Chemical studies on the deterioration of palm oil
(Department of Chemistry, Obafemi Awolowo University., 1983) OKIY, Dere Arubore
The work reported in this thesis is on the chemical changes which take place when palm oil is subjected to thermal deterioration and the effect on the nutritional value of leaf protein. The state of deteriorated palm oil on the nutritional value of leaf protein as determined by PER, BV, NPU and TD were examined; this was not worse than diets without the oil samples.
Open Access
Development and performance testing of an electrochemical treatment process for selected industrial wastewaters
(Department of Civil Engineering, Falculty of Technology Obafemi Awolowo University, 2006) Isalah Adesola OKE
The study investigated the treatment of selected industrial wastewaters electrochemically with a view to developing a system that would remove pollutants from wastewaters effectively without losing much of the electrodes. The study concluded that the electronical treatment method was effective and could be used along side with conventional treatment processes.
Open Access
Effects of asunle dumpsite, Obafemi Awolowo University, Ile-Ife on the spatio-temporal variations in water quality and ambient polycyclic aromatic hydrocarbon (PAH) levels.
(Institute of Ecology and Environmental studies, Faculty of Science, Obafemi Awolowo University., 2022) Adebayo, Abdulquddus Adelayo
This study characterised the solid waste of Asunle Dumpsite, Obafemi Awolowo University, Ile-Ife and the polycyclic Aromatic Hydrocarbon (PAH) congeners of ambient air within three kilometers radius of the dumpsite. It determined the physico-chemical characteristics and plankton composition of water within 500m radius of the dumpsite . It also assessed of the efficacy of institutional, financial and legal frameworks established for the management of the dumpsite. These were with the view to determine the effects of Asunle dumpsite on the spatio-temporal variations in water quality and ambient PAH levels
Open Access
EFFECTS OF ASUNLE DUMPSITE, OBAFEMI AWOLOWO UNIVERSITY, ILE-IFE ON THE SPATIO-TEMPORAL VARIATIONS IN WATER QUALITY AND AMBIENT POLYCYCLIC AROMATIC HYDROCARBON (PAH) LEVELS
(INSTITUTE OF ECOLOGY AND ENVIRONMENTAL STUDIES, FACULTY OF SCIENCE, OBAFEMI AWOLOWO UNIVERSITY., 2022) ABDULQUDDUS ADELAYO ADEBAYO
This study characterised the solid waste of Asunle Dumpsite, Obafemi Awolowo University, Ile-Ife and the Polycyclic Aromatic Hydrocarbon (PAH) congeners of ambient air within three kilometre radius of the dumpsite. It determined the physico-chemical characteristics and plankton composition of water within 500 m radius of the dumpsite. It alsodumpsite. It assessed the efficacy of institutional, financial and legal frameworks established for the management of the dumpsite. These were with the view to determining the effects of Asunle dumpsite on the spatio-temporal variations in water quality and ambient PAH levels. The multi-stage sampling method was used to characterise Asunle dumpsite. The dumpsite was divided into 100 pixels and classified into four sections based on estimated waste heap. Four pixels were randomly selected from each category for waste characterisation into type and quantity. One air sampling station was located in the dumpsite and three others at 1 km distance from the dumpsite. Ambient air samples were collected using polyurethane foam (PUF) passive samplers fabricated in line with the modified Annex 3 of the South Pacific regional project passive air sampling protocol. PAHs trapped in each recovered PUF were extracted and quantitative analysis of PAHs in the samples was achieved using Gas Chromatography-Mass Spectrometer (GC-MS). Seventy-two water samples were collected upstream, dumpsite impact site and downstream of an adjoining stream once every month for 12 months. Temperature, pH, and conductivity were determined insitu. Water samples for analysis of other parameters were collected in 2.0 L plastic bottles. The physicochemical parameters were analysed using standard instrumental and non-instrumental methods. Heavy metals were analysed using Atomic Absorption Spectrometer. Plankton distribution and abundance were assessed by straining 30 L of water and examining under the microscope to identify species present using appropriate identification keys according to standard methods. Data obtained were analysed using Student T-test, ANOVA, correlation coefficient and regression analyses as appropriate
Open Access
GEOPHYSICAL ASSESSMENT FOR CARBON DIOXIDE (CO2) SEQUESTRATION IN “IT” FIELD, NIGER DELTA, NIGERIA
(Department Of Physics And Engineering Physics, Faculty Of Sciences, Obafemi Awolowo University Ile-Ife., 2022) ADENIKA Charles Itunu
This study established the fault framework of theThis study established the fault framework of the reservoir environment, identified suitable reservoirs, determined petrophysical parameters of the identified reservoirs, estimated the storage capacity of the reservoirs and determined the sealing efficiency within IT field Niger Delta, Nigeria. These were with a view to assessing the suitability and utilization of IT field for implementation of geological CO2 sequestration. High resolution aeromagnetic, 3D seismic and well log data were used. The magnetic data were gridded, reduced to equator and upward continued to produce residual magnetic intensity (RMI) map. Quantitative processes were applied on the RMI to estimate the sedimentary thickness and delineate lineaments on a regional scale. Hydrocarbon reservoirs were mapped and their petrophysical parameters computed from well log data. Fault and horizon mapping were carried out on the vertical seismic sections to produce structural maps. The structural maps and petrophysical parameters obtained were used to determine the storage capacities of the identified hydrocarbon reservoirs. The calculated volume of shale (Vshale) was used to generate fault models which were used to evaluate the sealing efficiency of the mapped faults. Compressional wave velocity (Vp) and shear wave velocity (Vs) obtained from identified reservoirs and shales (caprocks) were used to compute, model and analyze geomechanical parameters to deduce the sealing efficiency of the identified reservoirs and caprocks. The results showed that the sedimentary thickness ranged from 2.5 km to 21.5 km with a mean of 10 km. The basement structures delineated trended majorly in the NE-SW direction and were deep seated structures which may not influence the overburden. Three sand reservoirs; RES-1, RES-2 and RES-3, were identified and mapped across six wells (IT-01 to IT-06). Results of petrophysical analysis revealed gross thickness values of 145.25, 98.86 and 474.94 ft; porosity values of 0.29, 0.22 and 0.27; hydrocarbon saturation values of 0.29, 0.45 and 0.64; permeability values of 3890, 243.24 and 2401.95 mD; and Net-to-Gross values of 0.90, 0.36 and 0.69 for RES-1, RES-2 and RES-3 respectively. The storage capacity computed from the petrophysical and volumetric analyses, and storage efficiency factors for RES-1, RES-2 and RES-3 using DOE model (1% and 4%) revealed 49.42 Mtons and 197.77 Mtons; 16.00 Mtons and 64.02 Mtons, and 1.35 Gtons and 5.67 Gtons; respectively. According to Goodman’s model (10% and 15%), RES-1, RES-2 and RES-3 were estimated to have storage capacity of 494.30 Mtons and 741.45 Mtons; 160.00 Mtons and 240.07 Mtons, and 13.52 Gtons and 20.29 Gtons; respectively. RES-3 was adjudged the reservoir with the largest storage capacity. Fault seal analyses revealed that fault sealing percentages ranged from 20 – 60 %, indicating that the reservoirs are assisted by moderately sealing faults which are capable of sealing the reservoir for a longer period. Geomechanical analyses revealed that the identified reservoirs and caprocks are ductile and possess sufficient strength to withstand external pressure. The study concluded that IT field contain reservoirs which have moderate fault seal capacity, appreciably thick caprocks with very good storage capacity thereby indicating that the field is capable of hosting CO2 sequestration. xviii identified suitable reservoirs, determined petrophysical parameters of the identified reservoirs, estimated the storage capacity of the reservoirs and determined the sealing efficiency within IT field Niger Delta, Nigeria. These were with a view to assessing the suitability and utilization of IT field for implementation of geological CO2 sequestration. High resolution aeromagnetic, 3D seismic and well log data were used. The magnetic data were gridded, reduced to equator and upward continued to produce residual magnetic intensity (RMI) map. Quantitative processes were applied on the RMI to estimate the sedimentary thickness and delineate lineaments on a regional scale. Hydrocarbon reservoirs were mapped and their petrophysical parameters computed from well log data. Fault and horizon mapping were carried out on the vertical seismic sections to produce structural maps. The structural maps and petrophysical parameters obtained were used to determine the storage capacities of the identified hydrocarbon reservoirs. The calculated volume of shale (Vshale) was used to generate fault models which were used to evaluate the sealing efficiency of the mapped faults. Compressional wave velocity (Vp) and shear wave velocity (Vs) obtained from identified reservoirs and shales (caprocks) were used to compute, model and analyze geomechanical parameters to deduce the sealing efficiency of the identified reservoirs and caprocks. The results showed that the sedimentary thickness ranged from 2.5 km to 21.5 km with a mean of 10 km. The basement structures delineated trended majorly in the NE-SW direction and were deep seated structures which may not influence the overburden. Three sand reservoirs; RES-1, RES-2 and RES-3, were identified and mapped across six wells (IT-01 to IT-06). Results of petrophysical analysis revealed gross thickness values of 145.25, 98.86 and 474.94 ft; porosity values of 0.29, 0.22 and 0.27; hydrocarbon saturation values of 0.29, 0.45 and 0.64; permeability values of 3890, 243.24 and 2401.95 mD; and Net-to-Gross values of 0.90, 0.36 and 0.69 for RES-1, RES-2 and RES-3 respectively. The storage capacity computed from the petrophysical and volumetric analyses, and storage efficiency factors for RES-1, RES-2 and RES-3 using DOE model (1% and 4%) revealed 49.42 Mtons and 197.77 Mtons; 16.00 Mtons and 64.02 Mtons, and 1.35 Gtons and 5.67 Gtons; respectively. According to Goodman’s model (10% and 15%), RES-1, RES-2 and RES-3 were estimated to have storage capacity of 494.30 Mtons and 741.45 Mtons; 160.00 Mtons and 240.07 Mtons, and 13.52 Gtons and 20.29 Gtons; respectively. RES-3 was adjudged the reservoir with the largest storage capacity. Fault seal analyses revealed that fault sealing percentages ranged from 20 – 60 %, indicating that the reservoirs are assisted by moderately sealing faults which are capable of sealing the reservoir for a longer period. Geomechanical analyses revealed that the identified reservoirs and caprocks are ductile and possess sufficient strength to withstand external pressure. The study concluded that IT field contain reservoirs which have moderate fault seal capacity, appreciably thick caprocks with very good storage capacity thereby indicating that the field is capable of hosting CO2 sequestration.
Open Access
Intergrated Explorations and Statistical Studies of Geochemical Data of Amphibolites in Ife-Ilesa Gold Field
(Department of Geology, Faculty of Science, Obafemi Awolowo University., 1988) Ajayi, Taiwo Rufus
In the Ife-Ilesa schist belt, occurrence of alluvial gold is spatially related to the amphibolite complex which consists of mafic/ultramafic rocks and pelitic schists. The amphibolites constitute the most widespread mafic potential source rocks. An integrated exploration and statistical studies of geochemical data in this area was carried out to investigate the geochemical characteristics of the amphibolites, recognise and effectively delineate anomalous geochemical patterns related to potential areas of Au mineralization and evaluate geochemical and geological relationships.
Open Access
Inventorization and modelling of the emission of greenhouse pollutants in Nigeria
(Department of Physics, Obafemi Awolowo University, Ile-Ife, Nigeria., 1995) Imoh, Bassey Obioh.
The determination of the emission rates pathways for the emission of greenhouse gasses and other toxic air pollutants is carried out with a view to determining the sources and source strengths. This will enable the prognosis of emission pathways for the emission relevant processes as well as the modelling of the various impacts on the atmospheric environment in Nigeria.
Open Access
Molecular characterisation of rodent-dreived lassa virus and rodent host species in endemic foci for lassa fever within North-central and Southern Nigeria.
(Department of Biochemistry and Molecular biology, faculty of science, Obafemi Awolowo University., 2022) ADESINA Adetunji Samuel
This study determined the presence of Lassa virus (LASV) strains in rodent populationsin the study area, characterised the Lassa virus strains phylogenetically, established the association between Lassa virus infection and lineage distribution in rodent hosts and analysedgenetic variability between Lassa virus strains detected within the study areas. These were witha view to providing information on Lassa virus incidence in rodent populations, lineage andstrain distribution of the virus across the study areas. Non endemic (Kwara), endemic (Nasarawa, Plateau) and highly endemic (Edo, Ondo, Ebonyi) States were selected as sampling sites based on epidemiological data from the NigeriaCenter for Disease Control (NCDC). Identification of captured rodents was based onmorphology and molecular characterisation by targeting the cytochrome b (Cyt b) gene, usingPolymerase Chain Reaction (PCR)-based analysis of DNA extracted from kidney samples. To investigate previous exposure of rodents to LASV, Immunoglobulin G (IgG) antibody testingwas carried out by immunofluorescence assay (IFA). Ongoing LASV infection was investigated by screening rodent blood samples using quantitative reverse transcriptase-PCR(qRT-PCR) targeting the LASV gene. All positive samples from the qRT-PCR were then runon a gel-based reverse transcriptase-PCR (RT-PCR) targeting fragments of the Large (340 bp),Glycoprotein Precursor Complex (1 kb) and Nucleoprotein (800 bp) genes. Phylogenetic analysis tools (BEAST, MAFFT alignment software and IQTree) were used to determine LASV lineage distribution of positive rodents. Statistical analysis was carried out using the GraphPad Prism 9 software.Six hundred and eleven (611) small mammal specimens were trapped in this study, representing 10 rodent and one shrew species. The Mastomys rodents were the most abundant (40.10%) and were present in every location. Five species (Mastomys natalensis, n = 30; Mastomys erythroleucus, n = 18; Praomys daltoni, n = 9; Mus musculus, n = 4; and Crocidura spp, n = 1) were seropositive for LASV. Overall IgG seropralevence was 10.14%, with Edo andOndo States having the highest number of IgG-positive rodents. Molecular testing showed thatM. erythroleucus rodents from Ebudin (n = 6, 16.67%) in Edo State and M. natalensis from Ebudin (n = 3, 11.54%) and Ekpoma (n = 5, 35.71%) in Edo State and Owo (13, 29.55%) in Ondo State, were PCR-positive. Mastomys erythroleucus was reported in only 3 States in the study area: Nasarawa (Lafia, n = 3, Obi, n = 1), Ebonyi (Ndubia, n = 26, Ndiawala, n = 39) and Edo (Ebudin, n = 36). Testing showed that 28 (26.67%) had some interaction with LASV with six being qRT-PCR-positive and 22 IgG-positive samples. Mastomys erythroleucus samples from Ndiawala (Ebonyi State) and Obi (Nasarawa State) had no interaction with LASV as revealed by both PCR and IgG antibody testing. Phylogenetic analysis of the L, GPC and NP genes of the LASV detected in this study showed that the virus belongs to lineage II. This study concluded that Mastomys erythroleucus is a host of LASV in southern Nigeria and the sequences belong to lineage II. Moreover, Lassa virus antibody was found to be present in previously unreported rodent species.
Open Access
Moss, surface runoff and associated sediments as indicators of metal and trace organic pollution in Lagos, Ile Ife and Osogbo areas
(Department of Chemistry Obafemi Awolowo University, 2000) OGUNFOWOKAN Aderemi Okunola
The levels of sediments and mosses (PAHs) and trace elemental composition of runoff and associated sediments and road side moss samples, Barbula lambarenesis (p.vard) were determined by Gas-liquid chromatography- mass spectrometry (GC_MS), Atomic absorption (AAS) and capillary Electrophoresis n(CE) techniques. The aims of the study were to develop a simple and efficient procedure for the GC_MS measurement and identification of PAHs in surface runoffs, sediments and mosses of Lagos, Ile-Ife and Osogbo areas determine areas
Open Access
Phase transitions in some metal 10-hydroxy and 9, 10-dihydroxyotadecanoates.
(Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria., 1992) Prince, Chukwulozie Mbaneme.
This work reports the conductance of some metal carboxylate systems and the enthalpy/entropy of phase transition of the systems. The objective was to study the physical properties of new compounds (10-hydroxyotadecanoates and 9, 10-dihydroxyotadecanoates of lead, zinc, cadmium and mercury) with a view to examiing their usefulness as materials with potential technology applications.

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