255 research outputs found
Indigenous technology as a basis for science and technology education in junior secondary schools : a Sierra Leonean case study
No full textThis study investigates two issues: a) the usefulness of indigenous technology as an approach for teaching science and technology to junior pupils of secondary schools in Sierra Leone. b) the factors which influence its implementation. In order to carry out this investigation, the author developed a fifteen lesson module on energy, using the `coalpot', a significant indigenous technology device as centre-piece. The module was tried out in three schools in Sierra Leone, using a total of 224 pupils. Other members of the sample were experimental teachers (who taught the module) and non-experimental (who only evaluated it) and science educators. Using the triangulation method, data were collected by achievement tests, questionnaires, structured and unstructured observations and informal discussions. The results were statistically analyzed using the SPSS/PC and Minitab Computer packages. It emerged from the findings that indigenous technology is a useful approach for teaching science to junior secondary school pupils, irrespective of the problems encountered. The post-achievement test results show that on the whole, the module had a positive effect on pupils' learning. The study also shows that indigenous technology has the potential to generate pupils' interest and improve their attitudes towards science. The factors which can become barriers to the implementation of an innovation like this one, were identified and shown to be teacher- and school-related. It is recommended among other things that science education researchers, teacher trainers, curriculum developers and teachers collaborate to develop and document instructional materials based on indigenous technology. That indigenous technology be incorporated into teacher training methodology courses so that trainee teachers will have a longer period to become familiar with both the content and the teaching strategies that may be used.</p
Opening the ‘black box’ of national digital identity systems: another invisible border for Africans?
No full textBiometric digital identity systems have been promoted as a solution for Africa’s development challenges. By providing accurate and reliable identification of citizens, these systems are expected to enable better planning and resource allocation by states. However, this optimistic view overlooks the border logic embedded in the design and deployment of these systems. In this article, the author critically examines the assumptions and implications of biometric digital identity systems in Africa. By broadening the debate on the intersection of African ‘mobilities’, responsible innovation, and the deployment of biometric technology, the author attempt to pry open the ‘black box’ of national digital identity systems and contends that the diffusion of these systems in Africa is driven more by the Global North’s border interests than by the local populations’ development needs.
Geochemical Classification and Geotectonic Setting of Granitic Gneisses from Southeastern Margin of Western Nigeria Basement
No full textChemical whole-rock major oxides and some trace element analyses were done on granitic-gneiss rocks from Dagbala-Atte District, located on the southeastern margin of western Nigeria Basement Complex. This was meant to classify the rocks and to understand the tectonic setting in order to evaluate their crustal evolution. The chemical analyses were done using inductively-coupled plasma mass spectrometer. From the results obtained, these rocks classified into calc-alkaline to shoshonite series with metaluminous to peraluminous varieties. They are I-type granitoids of feroan composition. The granitic gneisses formed from metamorphism of granite and granodiorite. Tectonically, most of the rock samples plotted in the field of island arc, continental arc and continental-collisional granitoids,which indicated that the protolith granite and granodiorite are orogenic and are arc related inferring arc tectonic setting
Production of CO-rich Hydrogen Gas from Methane Dry Reforming over Co/CeO2 Catalyst
Get PDFProduction of CO-rich hydrogen gas from methane dry reforming was investigated over CeO2-supported Co catalyst. The catalyst was synthesized by wet impregnation and subsequently characterized by field emission scanning electron microscope (FESEM), energy dispersion X-ray spectroscopy (EDX), liquid N2 adsorption-desorption, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) for the structure, surface and thermal properties. The catalytic activity test of the Co/CeO2 was investigated between 923-1023 K under reaction conditions in a stainless steel fixed bed reactor. The composition of the products (CO2 and H2) from the methane dry reforming reaction was measured by gas chromatography (GC) coupled with thermal conductivity detector (TCD). The effects of feed ratios and reaction temperatures were investigated on the catalytic activity toward product selectivity, yield, and syngas ratio. Significantly, the selectivity and yield of both H2 and CO increases with feed ratio and temperature. However, the catalyst shows higher activity towards CO selectivity. The highest H2 and CO selectivity of 19.56% and 20.95% respectively were obtained at 1023 K while the highest yield of 41.98% and 38.05% were recorded for H2 and CO under the same condition
Influence of oxalate ligand functionalization on Co/ZSM-5 activity in Fischer Tropsch synthesis and hydrodeoxygenation of oleic acid into hydrocarbon fuels
No full textAbstractAchieving high degree of active metal dispersions at the highest possible metal loading and high reducibility of the metal remains a challenge in Fischer Tropsch synthesis (FTS) as well as in hydrogeoxygenation (HDO).This study therefore reports the influence of oxalic acid (OxA) functionalization on the metal dispersion, reducibility and activity of Co supported ZSM-5 catalyst in FTS and HDO of oleic acid into paraffin biofuel. The Brunauer–Emmett–Teller (BET) results showed that cobalt oxalate supported ZSM-5 catalyst (CoOx/ZSM-5) synthesized from the incorporation of freshly prepared cobalt oxalate complex into ZSM-5 displayed increase in surface area, pore volume and average pore size while the nonfunctionalized cobalt supported on ZSM-5 (Co/ZSM-5) catalyst showed reduction in those properties. Furthermore, both XRD and XPS confirmed the presence of Co° formed from the decomposition of CoOx during calcination of CoOx/ZSM-5 under inert atmosphere. The HRTEM showed that Co species average particle sizes were smaller in CoOx/ZSM-5 than in Co/ZSM-5, and in addition, CoOx/ZSM-5 shows a clear higher degree of active metal dispersion. The FTS result showed that at CO conversion over Co/ZSM-5 and CoOx/ZSM-5 catalysts were 74.28% and 94.23% and their selectivity to C5+ HC production were 63.15% and 75.4%, respectively at 4 h TOS. The HDO result also showed that the CoOx/ZSM-5 has higher OA conversion of 92% compared to 59% over Co/ZSM-5. In addition CoOx/ZSM-5 showed higher HDO and isomerization activities compared to Co/ZSM-5.</jats:p
Wealth, household heterogeneity and livelihood diversification of Fulani pastoralists in the Kachia Grazing Reserve, northern Nigeria, during a period of social transition
Get PDFBACKGROUND: A mixed methods study was undertaken in the Kachia Grazing Reserve of northern Nigeria. Surveys in March, June and October 2011 included focus group discussions, key informant and in-depth household interviews, concerning livelihood practices, animal health, ownership, and productivity. In May 2011, 249 Fulani families fleeing post-election violence entered the reserve with their livestock, increasing the number of households by one third.RESULTS: Despite being settled within a grazing reserve, over half of households sent all their cattle away on seasonal transhumance and another third sent some away. Cattle accounted for 96% of total tropical livestock units (TLU), of which 26% were cattle kept permanently outside the reserve. While all households cited livestock as their main source of income, 90% grew crops and 55% derived income from off-farm activities. A multiple correspondence analysis showed that for each extra member of a household its TLU value increased by 2.0 [95% CI, 1.4-2.7], while for each additional marriage its TLU increased by 15.7 [95% CI, 7.1-24.3]. A strong association was also observed between small herds, small households with only one wife, alongside marked geographical wealth differences within the reserve. New immigrant families had larger household sizes (33) and livestock holdings (122 TLU) than old settlers (22 people and 67 TLU). Prior to the mass immigration, the distribution of TLU per person was unimodal: 41% of households were classified as 'poor' and 27% as 'medium', whereas post-immigration it was bi-modal, with 26% classified as 'very poor' and 28% as 'medium'.CONCLUSIONS: While cattle remain the principal source of Fulani income and wealth, the inhabitants of Kachia Grazing Reserve have diversified their livelihood strategies to respond to changing circumstances and stress, especially the limited availability of grazing within the reserve and political insecurity outside, resulting in continued transhumance, the maintenance of smaller livestock holdings and pushing households into poverty.</p
Effects of Pension Fund Assets on Capital Market Performance in Nigeria
No full textThis research looked into how pension funds held over a long stretch can provide a lot of capital to the market in the long term rather than giving out speculative capital over a short period. It studied how pension funds impact capital market performance in Nigeria. To do this, data from the quarterly reports of National Pension Commission and the Central Bank of Nigeria Statistical Bulletin from 2014 to 2019 (spanning 24 quarters) was used. The sample group was comprised of 50 companies, including 24 Pension Fund Administrators. This study looked into seven Closed Pension Fund Administrators (CPFAs) and nineteen Approved Existing Schemes (AESs). Everyone was included in the research, and it was conducted by looking at what happened in the past. Analysing the data collected from a secondary source, it was found that private equity had a noticeable effect on the financial market in Nigeria. It was recommended that the government should make policies to make sure more people invest in private equity, since it helps the Nigerian financial market. The results also showed that the regulations by the government weren't doing enough to get pension reform and economic reform to link up, and there were other problems with the regulations that didn't help create trust in the reform.Corresponding Author: Oluyemi Ayodele OLONIT
Interactive Effect of Blackeye cowpea mosaic virus and Cucumber mosaic virus on Vigna unguiculata
No full textThis research tries to demonstrate physiological effect of combined infection of two viruses on growth parameter of cowpea plant as demonstrated through symptom expression. Blackeye cowpea mosaic virus (BlCMV) and Cucumber mosaic virus (CMV) were transmitted to cowpea plants by mechanical rub inoculation. This study showed that the differences in stem height and final aboveground fresh weight of cowpea plants inoculated with mixed infection with CMV and BlCMV were significantly less than those of plants inoculated with a single virus. Likewise cowpea plants inoculated with either virus alone or with CMV and BlCMV mixed infection had less stem height and aboveground fresh weight than the control. The mixed infection of BlCMV and CMV caused significant increase in the severity of symptoms in cowpea and also in the height using factors analysis and Abbott's equation. Symptom severity rating scale used, demonstrated statistical proof for physiological effect based on symptom severity for co-infection. A three phase disease symptom severity expression revealed disease severity for each viral treatment associated with host plant. Keywords: cowpea, virus mixed infection, interaction, severity, sympto
Artificial intelligence modelling approach for the prediction of CO-rich hydrogen production rate from methane dry reforming
Get PDFThis study investigates the applicability of the Leven–Marquardt algorithm, Bayesian regularization, and a scaled conjugate gradient algorithm as training algorithms for an artificial neural network (ANN) predictively modeling the rate of CO and H2 production by methane dry reforming over a Co/Pr2O3 catalyst. The dataset employed for the ANN modeling was obtained using a central composite experimental design. The input parameters consisted of CH4 partial pressure, CO2 partial pressure, and reaction temperature, while the target parameters included the rate of CO and H2 production. A neural network architecture of 3 13 2, 3 15 2, and 3 15 2 representing the input layer, hidden neuron layer, and target (output) layer were employed for the Leven–Marquardt, Bayesian regularization, and scaled conjugate gradient training algorithms, respectively. The ANN training with each of the algorithms resulted in an accurate prediction of the rate of CO and H2 production. The best prediction was, however, obtained using the Bayesian regularization algorithm with the lowest standard error of estimates (SEE). The high values of coefficient of determination (R2 > 0.9) obtained from the parity plots are an indication that the predicted rates of CO and H2 production were strongly correlated with the observed values
Characterising Real Estate Value as Co-determinant of Housing Choice Optimality in Nigeria
Get PDFNigeria remains classified as a lower middle-income nation. Among middle-income households (MIHs), there exists an idea that real estate value is central to housing well-being, but the significance of the anecdote has not been empirically established.The principal aim of this study is to characterise real estate value (REV) as a co-determinant of optimality, the adopted proxy for housing well-being, through regression modelling of selected MIHs in Abuja and Minna, Nigeria. This study examined the impact of REV as well as the effects of four other pertinent variables (household income, commuting cost, workplace distance and household activity pattern) on housing choice optimality in Nigeria. Using primary and secondary data from purposively selected MIHs in Abuja and Minna, the study employed multiple regression to explore the relationships among the variables. The results show that the housing optimality model has a reasonable predictive explanation of approximately 57% - 77% for the explanatory variables. The study's findings also reveal that household income, real estate value and activity patterns have significant effects on housing choice optimality, albeit with varying magnitudes across the two cities. It is worth noting that the t-statistic ranges between -5.20(Abuja) and -2.12(Minna), thus implying that REV impacts optimality negatively and that REV is a burden which households must bear in order to secure the right to an apartment of their choices. The study concludes that given the real estate value, the consequential housing choice optimality could be predicted across different housing markets in Nigeria as a decision-support guide for rental seekers. Furthermore, given the consistency of these results with earlier studies, this work provides greater knowledge on the lifecycle of housing choices and realities in Nigeria. By adapting and extending the optimality idea to real estate, this study has made an important contribution to the discourse of optimal rental housing.
 
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