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

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Acta Geochimica 2018年第4期37卷 592-613页

作者： Abiola Oyebamiji Adegbola Odebunmi Hu Ruizhong Atta Rasool State Key Laboratory of Ore Deposit Geochemistry Instituteof Geochemistry Chinese Academy of SciencesGuiyang 550081 China Department of Geological Services Ogun State Ministry of Commerce and Industry Oke-Mosan Abeokuta Nigeria University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of SciencesGuiyang 550081 China Department of Science Laboratory Technology Ekiti StateUniversity Ado-Ekiti Ekiti State 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 ***-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 *** Pearson correlation showed that there were significant positive associations among selected metals in soil and stream sediment samples.

关键词： Trace metals Stream sediments Geo-accumulation index - PCA Soil southwestern nigeria

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A Multimodal Critical Study of Selected Political Rally Campaign Discourse of 2011 Elections in southwestern nigeria

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Language and Semiotic Studies 2020年第3期6卷 72-95页

作者： Mohammed Ademilokun Moji Olateju Obafemi Awolowo University Nigeria

Multimodal communication is at the heart of political *** 2011 electioneering campaigns in nigeria witnessed an interesting use of multimodal resources for the expression of *** 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 *** 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 *** 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 *** study further shows that cultural and political identities are strategically used for political marketing and legitimation through the political campaign *** is also enacted in the renegotiation of gender ideology and the hegemonic configuration of 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.

关键词： campaign discourse critical multimodal analysis politics political rally southwestern nigeria 2011 elections

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Epidemiological Review of Macular Hole in Ekiti, southwestern nigeria

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Open Journal of Ophthalmology 2020年第4期10卷 276-282页

作者： Iyiade A. Ajayi Olusola J. Omotoye Stella Adegbehingbe Department of Ophthalmology Ekiti State University Teaching Hospital Ado-Ekiti Nigeria Department of Ophthalmology State Specialist Hospital Akure 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.

关键词： Macular Hole southwestern nigeria Epidemiological Review Central Visual Defect

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The Geochemistry of Carbonate Rocks in Igwe Igarra, southwestern nigeria

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International Journal of Geosciences 2023年第6期14卷 505-514页

作者： Jumoke Mujidat Omodeni Department of SLT (Geology/Mining) Ekiti State University Ado Ekiti 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.

关键词： Carbonate Rocks Geochemistry Igwe Area Photomicrograph southwestern nigeria

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

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Journal of Water Resource and Protection 2016年第3期8卷 311-329页

作者： Nicholas U. Ugwu Rubeni T. Ranganai Rapelang E. Simon Ghebrebrhan Ogubazghi Department of Physics University of Botswana Gaborone Botswana The Federal Polytechnic Ede Ede Nigeria Eritrea Institute of Technology Mai Nefhi Asmara Eritrea

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%.

关键词： southwestern nigeria Crystalline Rocks Electrical Resistivity Groundwater Potential Vulnerability Mapping

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Variation in soil properties in a transformed ecosystem in southwestern nigeria

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Journal of Agricultural Science and Technology 2009年第12期3卷 30-35页

作者： Ojo Abel Folorunso Kadeba Olatunji Kavode Joshua Department of Afforestation Ministry of Lands Housing and Environment Ado-Ekiti 360101 Nigeria Department of Forestry and Wood Technology Federal University of Technology Akure 340271 Nigeria Department of Plant Science University of Ado-Ekiti Ado-Ekiti 360101 Nigeria

Variation in soil properties as a result of the conversion of the tropical rainforest to a monospecific plantation of teak, tectona grandis, was examined in Akure forest reserve in southwestern nigeria. Comparison was made in the active rooting zone of 50 cm soil depth. It was discovered that there were no significant differences in the physical properties except in the value of organic matter content at the top 10 cm layer but chemical properties such as the pH and organic carbon changed significantly at the top 10 cm layer. Differences in other chemical properties, such as the available P, exchangeable cations K, Ca and Mg, the exchangeable acidity and the cation exchange capacity were minor. This showed that no nutrient was limiting or was likely to be limiting in the soil for subsequent short rotation of plantation development.

关键词： soil properties transformed ecosystem southwestern nigeria

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