The Geochemistry of Carbonate Rocks in Igwe Igarra, Southwestern Nigeria

Nigeria has an abundance of valuable solid minerals and rocks which can generate revenue for the government if they are fully exploited. Carbonate rock is one of such rocks that occur prominently in Igwe Igarra area of Edo State. Five (5) carbonate rock samples (Four marble and One Calcsilicate) were subjected to geochemical analyses. A petrographic study reveals that marble and calcsilicate contain calcite, quartz, microcline, plagioclase, biotite and opaque minerals. Geochemical data shows that carbonate rocks have variable geochemical characteristics: Igwe marble is highly Calcitic (96% - 98%) and very low in dolomite Mg(CO3). Calcsilicate rock is low in CaO (27.5%) and higher in marble. The Igwe marble is pure and contains fewer impurities compared to calcsilicate rock which makes it unideal for usage. Based on these characteristics the marble from Igwe is suitable as raw materials for the productions of glass, papers, beet sugar, aggregates, lubricants and fillers.

Geoelectric Evaluation of Groundwater Potential and Vulnerability of Overburden Aquifers at Onibu-Eja Active Open Dumpsite, Osogbo, Southwestern Nigeria

Electrical resistivity method was used to assess groundwater potential and vulnerability of overburden aquifers at Onibu-Eja active open dumpsite, Osogbo, Southwestern Nigeria. Eighteen Vertical Electrical Sounding (VES) points and five 2-D imaging profiles established in five traverses at the periphery of the dumpsite were surveyed and analysed. The subsurface comprised of thin topsoil (resistivity 65 - 998 Ωm);heterogeneous weathered layer with resistivity 63 - 333 Ωm and thickness 0.7 - 8.5 m;weathered basement (resistivity 31 - 1253 Ωm and thickness 0.7 - 27.0 m) and fractured/fresh basement (resistivity 36 - 6213 Ωm). The 2-D inverse model of the profiles delineated low resistivity values ranging from 5 to 100 Ωm at a depth range of 10 - 20 m along traverses TR1-TR3 which is attributed to leachate percolation close to the dumpsite. The weathered basement was inclined relative to the dumpsite. The total overburden thickness varies from 6.9 to 33.7 m, with 20 and 40 m generally recommended as productive for groundwater abstraction in Southwestern Nigeria occurring in 61% of the area. Further, about 85% of the weathered layer resistivity values fall within medium groundwater potential (100 - 250 Ωm) and high groundwater potential (>250 Ωm). The ranking of groundwater potential as a function of saprolite (weathered basement) resistivity showed that 72% of the study area is characterized by optimum weathering (20 - 100 Ωm) and is classified as good groundwater potential. Fractured basement covered <30% of the study area. The evaluation of aquifer protective capacity has helped to classify the area into moderate, weak and poor protective capacities with moderate protective capacity zone covering 72%.

Epidemiological Review of Macular Hole in Ekiti, Southwestern Nigeria

Background: Macular hole is a known cause of central visual defect with varying etiologies in different parts of the world. It was considered an untreatable condition until 1991 when varying treatment techniques began to emerge with resultant restoration of central vision. This study was carried out to evaluate the prevalence and pattern of Macular hole in a tertiary eye centre in Nigeria. Method: This is a prospective hospital-based study over a 5 year period spanning from November 2013 to October 2018. All patients with macular hole seen within this period were included in the study. Relevant data were recorded with a structured questionnaire and analysed with SPSS version 20. Results: There were 46 eyes of 42 patients which constituted about 0.5% of all new patients seen over the study period. Male to female ratio was 1:1.3 with age ranged between 15 and 91years (mean = 61.8 ± 16.5 years). The majority of the patients (95.7%) had Idiopathic macular hole. Half of the patients (54.8%) had visual acuity less than 3/60 in the affected eye at the time of presentation. The majority (95.7%) of the patients did not accept the recommended surgical treatment option because of financial incapacitation. Conclusion: Macular hole is a disease of marked visual consequence. Available treatment option is still not within the reach of the majority because of the high cost.

Assessment of trace metals contamination in stream sediments and soils in Abuja leather mining, southwestern Nigeria

This study is aimed at determining the level of environmental degradation as well as the concentration of trace elements in soil and stream sediments in order to evaluate the environmental impact of the mining operation.Twenty-five(25) soils and ten(10) stream sediment samples were collected from the study area. The physicochemical parameters were determined using appropriate instrumentation with the aid of a digital p H meter(Milwaukee meter) to measure the p H and electrical conductivity, total dissolved solids, moisture content and loss on ignition of the soil and stream sediment samples. The p H of the soil sample ranged from(6.10 to 7.19); Electrical conductivity ranged from(21.3 to 279.4 μS/cm), moisture content varied from(0.60% to 7.20%), and the LOI ranged from(2.03% to 18.62%). The results of the analysis showed that the concentrations of the trace elements in the soils and stream sediment samples were slightly higher than the background values. Plots of the trace elements in stream sediment samples show moderate, consistent decrease downstream except at points where there was mine water discharge into the main river. The pollution levels of heavy metals were examined in stream sediment and soil samples using different assessable indices, such as the enrichment factor, which showed significant-moderate enrichment for Cr, Th, Nb, Zn, Pb, Y and Zr and the geoaccumulation index, which showed practically moderate contamination with Cr, Ni and Sr based on regional background reference values. Geo-accumulation index and contamination index for soils and stream sediment revealed uncontaminated to moderate contamination. Likewise,elements with moderate contamination were Cr, Ni and Sr.The Pearson correlation showed that there were significant positive associations among selected metals in soil and stream sediment samples.

Urban Gully Development in Southwestern Nigeria

This study examined the development of urban gullies in a part of Southwestern Nigeria. This was done with a view to determine the volume and amount of sediment loss from the 1st and 2nd order gullies in a cascade system. Twenty (20) towns were randomly selected from where thirty (30) gully systems comprising forty (40) 1st order and five (5) 2nd order gullies were measured with Tape and Total Station (TS). The gully dimensions measured include gully lengths, depths and cross sectional areas. The core samples were also taken from the study gullies for the determination of the soil bulk density. The results showed that the mean volume of soil loss from the 1st order and (2nd) order gullies in the study area are 1612.633 m3 and 1629.922 m3, respectively. The weight of the estimated sediment loss from the 1st order and 2nd order gullies are 2661.621 and 2657.318 tonnes, respectively. The result further showed that the total soil loss of 119661.442 tonnes was obtained from the study gullies and that the 1st order gullies accounted for 87% (106,375 tonnes) of the total soil loss. This was an indication of soil degradation in the area.

Diversity and Distribution of Spiders in Southwestern Nigeria

The study of diversity and distribution of spiders was carried out at Obafemi Awolowo University, Southwestern Nigeria, in wet and dry seasons between October 2012 and April 2014. Spiders were collected from five different sampling sites in the study area: cultivated land, open field, hill area, house dwelling and aquatic habitat. We found 1824 individuals belonging to 19 different spider families in the study area. 9 families of spiders were present in the hill habitat;12 families of spiders were present in the open field habitat;6 families of spiders were present in house habitat;9 families of spider were present in aquatic habitat. All the 19 families of spiders were present in cultivated habitat. Therefore, cultivated habitat hosted the largest number of spider families in the area of study while house dwellers hosted the least number of spider families. Spiders are evenly distributed among the five habitats in this study and the fifth habitat, teaching and research farm representing cultivated area has the highest distribution of spider species. All the species recorded in Southwestern Nigeria were found in this habitat. In conclusion, 19 different spider families are recorded in Obafemi Awolowo University, Nigeria, during this study. These have enriched the collection of spider in Natural History Museum, Obafemi Awolowo University, Southwestern Nigeria.

A Multimodal Critical Study of Selected Political Rally Campaign Discourse of 2011 Elections in Southwestern Nigeria

Multimodal communication is at the heart of political campaigns.The 2011 electioneering campaigns in Nigeria witnessed an interesting use of multimodal resources for the expression of meaning.While Ademilokun and Olateju(2016)examined and interpreted some of such multimodal elements from a descriptive perspective,the present study extends engagement with the subject as it seeks to tease out critical meanings embedded in the multimodal ensembles.Data for the study were purposively obtained from the collection of multimodal resources deployed in the Southwestern part of Nigeria during the 2011 electioneering campaigns in Nigeria.The study is hinged on the theoretical provisions of Machin and Mayr(2012).The study demonstrates that the multimodal resources in the 2011 electioneering campaigns in Southwestern Nigeria are purveyors of gender,carnivalesque and communal ideologies which are used largely for negotiating and perpetuating political and class hegemony.The study further shows that cultural and political identities are strategically used for political marketing and legitimation through the political campaign visuals.Power is also enacted in the renegotiation of gender ideology and the hegemonic configuration of the rallies.The study concludes that visuality in political rally communication in Nigeria is a useful index for ideologies and identities drawn upon for political survival by politicians and political parties in the nation.

Assessment of Wind Energy Potential as a Power Generation Source in Five Locations of South Western Nigeria

In this study, the wind speed characteristics and energy potential in five selected locations in the southwestern part of Nigeria were investigated using monthly mean wind speed data of 51 years obtained from the Nigeria Meteorological Agency. The data were subjected to the 2-parameter-Weibull and other statistical analyses. The outcome showed that the wind speed measured at a height of 10 m ranged from 1.3 to 13.2 m/s while the modal wind speed ranges from 3.0 to 5.9 m/s. 83.6% of the data were found to be greater than 3.0 m/s. The average monthly wind speed ranged from 2.72 to 7.72 m/s. Seasonally, average wind speeds ranged between 3.47 to 6.55 m/s and 3.83 to 6.94 m/s for dry (October to March) and wet (April to September) seasons, respectively. The two parameters of the Weibull statistics were found to lie between 2.99 ≤ k ≤ 5.32 and 3.02 ≤ c ≤ 8.57, respectively. The annual mean power densities are 65.09, 145.07, 176.96, 387.07 and 87.34 W/m2 for Abeokuta, Akure, Ibadan, Ikeja and Oshogbo respectively. It was further shown that the respective mean annual values of the most probable wind speed are 3.82, 4.97, 5.23, 7.03 and 4.01 m/s, while the annual values of the wind speed carrying maximum energy are 4.12, 5.48, 5.87, 7.50 and 4.55 m/s. These results indicate that wind speed has the viable potential for wind-to-electricity at height of 10 m for most of the locations assessed but it will be more viable in all the stations at a height above 10 m.