119 research outputs found
The Art of Preview in Appropriate Teaching/Learning Material Selection
This study recognised the importance of print materials and texts in effective and efficient teaching and learning. Though important, there is a proliferation of these materials in the market that learners, researchers and teachers cannot read all within the limited time available to them. They resort to the art of previewing to select the relevant ones. As previewers, they ought to look into the external and internal skeletons of materials such as textbooks, literature books, journal articles, essays and other continuous writings. The paper described skimming and scanning as important techniques for previewing. Finally, those elements and aspects of the English Language texts to be scanned or skimmed were looked at and the importance of each highlighted
Physicochemical properties of an acid ultisol subjected to different tillage practices and wood-ash amendment:Impact on heavy metal concentrations in soil and Castor plant
Production of Bricks for Building Construction and Predictability of Its Post-Fired Volume Shrinkage Based on Apparent Porosity and Water Absorption Capacity
ABSTRACT The high demand for durable building materials has led to the growing rate of production and application of bricks. Successful predictability of PostFired Volume Shrinkage (PFVS) was carried out based on its apparent porosity and water absorption capacity (WAC). The bricks were produced from clay which was prepared and processed, following a well detailed step-wise route. Prediction of the PFVS was carried out using a two-factorial empirical model expressed as; ϑ = -0.3988 ₰ -0.3789 ξ + 39.256 The validity of the derived model was rooted in the core expression ϑ -39.256 = -0.3988 ₰ -0.3789 ξ where both side of the expression correspondingly approximately equal. Results from both experiment and model prediction shows that decrease in PFVS resulted to increase in apparent porosity and WAC. This implied that the inter-particle spacing increased (with decreasing PFVS) to allow increased water absorption as result of increased apparent porosity. Results from evaluations indicated that the standard error incurred in predicting PFVS for each value of the WAC & apparent porosity considered, as obtained from experiment, derived model and regression model were 0.0842, 0.0010 and 0.0033 & 0.0834, 0.0011 and 4.2286 x 10 -5 % respectively. Furthermore the correlation between PFVS and WAC & apparent porosity as obtained from experiment, derived model and regression model were all > 0.97. The maximum deviation of the model-predicted water absorption (from experimental results) was less than 5.57%. This translated into over 94% operational confidence for the derived model as well as over 0.94 effective response coefficients of WAC and apparent porosity to PFVS of the bricks
Physicochemical Characterization of Farmland Affected by Automobile Wastes in Relation to Heavy Metal
Abstract: Selected properties of automobile waste and non-automobile waste (control) affected soils and its relation with some heavy metals were investigated in this study. Sampling site was delimited at each area by free survey technique and soil samples collected at the surface (0-20cm) and subsurface (20-40, 40-60cm) depth. Results of the study showed decreased Ca, k, Mg and CEC levels as well as increased Na content of the automobile waste affected soil compared to the control. Both soils were acidic in nature and their heavy metal contents decreased with depth. Higher levels of heavy metals above critical limits in automobile soils using standard were observed .Soil contents of P0 4 -, N0 3 -and sodium adsorption ratio (SAR) were within tolerable limits in both soils. The results indicate that automobile wastes had adverse effect on the nutrient level and fertility status of the studied soil
Effect of Rice Mill Wastes Application on Selected Soil Physical Properties and Maize Yield (Zea mays l.) On an Ultisol in Abakaliki Southeastern Nigeria
IMPACT OF AFRICAN FREE TRADE POLICY (AGREEMENT) ON THE SOCIO-ECONOMIC DEVELOPMENT OF NIGERIA
The signing of the agreement that established the African Continental Free Trade Area (AfCFTA) in the year 2019 is believed to be an African-based growth strategy that is self-reliant and is expected to be the world’s largest free trade area after the World Trade Organization (WTO). The agreement is an attestation to the fact that African countries cannot continue to rely solely on the global trading system and global economy of the world economic powers, probably because they are increasingly becoming unpredictable. However, there is an assumption that the aggregate consumer and business spending on the continent could rise if AfCFTA is implemented successfully. This assumption therefore calls for a research like this to evaluate the likely economic impacts of the free trade agreement on different African countries particularly Nigeria which is the giant of Africa and the focus of this study. To achieve the objectives of the study, descriptive statistical approach was utilized to examine how the AfCFTA could contribute particularly on poverty reduction and Nigeria has been struggling for many decades to reduce poverty. These variables were considered: household income, illiteracy level, unemployment level and access to health care. The results of the analyses revealed that the AfCFTA could be slightly beneficial to Nigeria as it would improve the efficiency of the factors of production and product markets thereby enhancing household income generation, reducing the level of illiteracy, unemployment and increasing access to good health, efficient resource allocation and improved industry competitiveness which was expected to help Nigeria record significant reduction in poverty level and increase in economic development. In the light of these findings, the study recommends that government should then design proactive strategies that would reap the full benefits of AfCFTA such as engaging the private sector in identifying receptive and risk surrounding their sectors and paying more attention to the development of the service sector etc. The study has potential limitations such as unavailability of recent data. To tackle this limitation, the study adopted the 2019 survey data on pillars of measuring human development index by World Bank to address the quality of the findings, and research question.
JEL: F10, H13, O10
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Heavy metals pollution potentials in the National Iron Ore Mining Company, Itakpe
Heavy metals pollution potential in National Iron Ore Mining Company, Itakpe was investigated. Two mining sites located at the east mining pits such as M3O, which is 370 m above sea level and M2O, which is 350 m above sea level were studied. Sequential extraction techniques was utilised to examine the distribution effect of the heavy metals pollution potential on the environment. Twelve representative (six-soil, two-sediment, two-plant and two-water) samples were collected, pre-treated and prepared for this study. The atomic absorption spectrometer was used to analyse the concentration of the metals after the sequential and single-stage extractions were determined. Results showed that Chromium, Arsenic, Cadmium and Copper are more bioavailable in the study area than Lead and Iron. This findings indicate that human, animals and plants are exposed to toxic elements (metals and metalloids)
Spheroidal graphite iron production of furnace roof hangers
The wire rod mill of the Ajaokuta Steel Company Limited produces coils, wire rods and re-bars of different sizes. Without the furnace hangers, it will be difficult for the mill to continue to operate. This paper describes the production of furnace roof hangers that are required for re-heating furnace using the spheroidal graphite iron (SGI), highlighting the sand-casting process, charge calculation, and the chemical compositions. The facilities within the foundry shop of the steel company are used to produce furnace roof hangers. The available materials used for the casting of the hangers are the pig iron, scrap ends, foundry returns and magnesium. The process of production was performed through the reheating furnace for the heating of 120 m x 120 m x 120 m billets. One ton induction furnace of low frequency was used as the melting vessel. Also, 6 kg of magnesium was introduced in the ladle before the liquid metal was teemed into it. A Spectro analytical instrument was used to determine the chemical compositions of the materials before and after the casting processes. The analysis of the chemical compositions of produced sample of SGI are presented and discussed
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