Microstructural characterisation, physical and chemical properties of rice husk ash as viable Pozzolan in building material: a case study of some Nigerian grown rice varieties

Recycling of agricultural wastes such as rice husk ash as pozzolan is being increasingly encouraged, particularly in developing countries. In this paper, preliminary investigation on the physical and chemical composit ions of r ice husk ash using different techniques was carried out. Scanning Electron Microscopy (SEM) images of the r ice husk ash showed residual p ores to be distributed within the ash sample, indicating th at the silica is a highly porous material with a large internal surface area . Samples burnt at 4000 C for 6 hours and 6000 C for 4 hours for ‘Bukus’ and ‘Soro/ Olomo nla’ show aggregates with clearly defined layers of loose flakes compared to ‘Faro 58’. The Energy dispersive x ray spectroscopy (EDX) analysis of rice husk ash performed to determine percentages of silica present in the samples were graphically represented. Nine elements (Al, Si, K, Ca, Br, Fe, Mg, Na, Mn) and their corresponding oxides (Al2O3 , SiO2 , K2O, CaO, Br, Fe2O3 , MgO, Na2 O, MnO) were detected with varying concentrations. The three varieties , on the average possess good silica content of over 50% considering the two varied temperature and time. Therefore , the chemical analysis results show that burning at combustion temperature of 6000 C for 4hrs, gives optimal result than at 4000 C for 6hrs because all the samples show high Silica content (Faro 58; 61.9, Bukus; 62.6 and Soro/Olomo nla; 59.5). Keywords : Rice husk ash, Scanning electron microscopy, Energy dispersive x - ray spectroscop

An Evaluation of the Influence of Corn Cob Ash on the Strength Parameters of Lateritic Soils

This paper reports the investigation of Corn Cob Ash as a pozzolan and a stabilizing agent for lateritic soils in road pavement construction.  Corn cob feedstock was obtained from Maya, a rural community in the derived savannah agro-ecological zone of South-Western Nigeria, and burnt to ashes of pozzolanic quality. Reddish brown silty clayey sand material, characterized as an A-2-6(3) material and  locally recognized as laterites was obtained from a borrow pit in Abeokuta, South-Western Nigeria and subjected to physical characterization tests according to BS 1377: 2000. The soil was subsequently mixed with CCA in varying percentages of 0%, 1.5%, 3%, 4.5%, 6% and 7.5% and the influence of CCA on the soil was determined for Liquid Limit, Plastic Limit, Compaction Characteristics, CBR and the Unconfined Compression Test. These tests were repeated on laterite-CCA-cement mix and laterite-cement mix respectively in order to detect any pozzolanicity in CCA when it combines with Portland cement and to compare results with a known soil stabilizing agent.  The result shows a similarity in the compaction characteristics of soil-cement, soil-CCA and soil-CCA-cement, in that with increasing addition of binder from 1.5% to 7.5%, Maximum Dry Density progressively declined while the OMC steadily increased. In terms of the strength parameters, the maximum positive impact was observed at 1.5% CCA addition for soil-CCA with a CBR value of 84% and a UCS value of 1.0MN/m2, compared with the control values of 65% and 0.4MN/m2 respectively. For the soil-CCA-cement mix, the strength parameters CBR and UCS continued to increase with increasing binder addition within the tested range for the ratios 1:2 and 1:1 and 2:1 CCA:cement. Significantly, the results from the soil-CCA-cement mix, indicate the pozzolanicity of CCA in that UCS values were higher by at least 14% for the 1:1 ratio, than was attained with the addition of only the corresponding quantity of cement. Keywords: Corn Cob Ash, pozzolan, CBR, UCS, biomass waste, road pavement

Beyond The Call of Duty: Realities of Work-Life Balance in the United Arab Emirates Education Sector

Previous research have been intrigued to assess the mechanisms used by employees to cope with tedious work schedules and other areas of their non-work lives. While there are yet to be sufficient studies that explore the countries in the Middle East, this paper aimed to explore the realities of WLB among professionals in the education sector in the United Arab Emirates (UAE). We further considered the implications of workplace and family support, and organisational culture on employees’ WLB and productivity. The study employs the use of qualitative data generated from semi-structured interviews of 41 lecturers across seven higher education institutions in Dubai, UAE aimed at investigating the various contexts of WLB

Automated classification of African embroidery patterns using cellular learning automata and support vector machines

Embroidery is the art that is majorly practised in Nigeria, which requires creativity and skills. However, differentiating between two standard embroidery patterns pose challenges to wearers of the patterns. This study developed a classification system to improve the embroiderer to user relationship. The specific characteristics are used as feature sets to classify two common African embroidery patterns (handmade and tinko) are shape, brightness, thickness and colour. The system developed and simulated in MATLAB 2016a environment employed Cellular Learning Automata (CLA) and Support Vector Machine (SVM) as its classifier. The classification performance of the proposed system was evaluated using precision, recall, and accuracy. The system obtained an average precision of 0.93, average recall of 0.81, and average accuracy of 0.97 in classifying the handmade and tinko embroidery patterns considered in this study. This study also presented an experimental result of three validation models for training and testing the dataset used in this study. The model developed an improved and refined embroiderer for eliminating stress related to the manual pattern identification process

THE EFFECT OF SUBSTITUTING MAIZE WITH GRADED LEVEL OF BISCUIT WASTE ON THE GROWTH PERFORMANCE, NUTRIENT UTILIZATION, CARCASS COMPOSITION, HAEMATOLOGICAL PARAMETERS AND ECONOMIC PERFORMANCE OF AFRICAN CATFISH Clarias gariepinus (BURCHELL 1822)

The effect of replacing maize with biscuit waste (BW) in the diet of Clarias gariepinus was evaluated in a 70-day feeding trial. Four isonitrogenous diets were prepared in which biscuit waste was used to replace maize at a rate of 50, 75 and 100% respectively. A diet without biscuit waste served as control. Each treatment had three replicates stocked with 10 catfish juveniles per tank with (mean initial body weight16.44±2.21g) per fish. The performance of the fish fed test diets was compared with fish fed a maize-based control diet containing 42.94% crude protein. The fish on the test diets performed better than the fish fed control diet with respect to mean weight gain (95.12±2.78g in BW 75 Vs 78.67±3.74g in control) and specific growth rate (3.04±0.04 %day-1 Vs 2.79±0.07 %day-1). Feed intake, feed conversion ratio and the protein efficiency ratio were not significantly different between test diets and the control. The inclusion of biscuit waste significantly improved (P<0.05) crude protein retention in the fish carcass. All the haematological parameters increased as a result of BW inclusion, the converse was however observed in cholesterol and triglyceraldehyde. There was significant difference (P<0.05) in the cost of feed intake and value of fish.Â

Antimicrobial Potentials of Uvaria Afzelli Scott-Elliot and Tetracera Alnifolia Willd Crude Extracts on Selected Human Pathogens: An In – Vitro Study

The antimicrobial activities of Uvaria afzelii Scott-Elliot root bark and Tetracera alnjfolia Willd leaf and root bark used in folklore medicine for the treatment of respiratory tract infections and superficial mycoses were studied. The chloroform and methanol extracts of the plants were screened against 3 Gram positive and 4 Gram-negative bacteria viz: Staphylococcus aureus UCH 2057, Streptococcus pneumoniae UCH 2034, Bacillus subtillis UCH 2033, Pseudomonas aeruginosa UCH 2058, Klebsiella species UCH 2046, Proteus mirabilis UCH 2055, and Escherichia coli UCH 2052. The activity of the crude extracts were also investigated on Candida albicans UCH STC 2036, Aspergillus niger PHM 1506, Trichophyton mentagrophyte ATCC 4808, Trichophyton rubrum ATCC 2894, Epidermophyton floccosum ATCC 110227 and Microsporum canis ATCC 11622. The agar diffusion and agar dilution methods were used for antimicrobial screening and determination of the minimum inhibitory concentrations (MIC) respectively. The methanol extracts of the plants at 10 mg/mL demonstrated the highest activity against most of the microorganisms tested. The M1C for the susceptible microorganisms ranged between 3.125 mg/mL to 50 mg/mL. Phytochemical screening of the plant samples revealed the presence of tannins, saponins, cardenolides and alkaloids and the absence of anthraquinones. The test organisms were resistant to the drug controls but were susceptible to the extracts of the plants. The antimicrobial activities of the plants extracts on the microorganisms tested justify their use in folklore medicine for the treatment of respiratory tract infections and superficial mycoses. Keywords: Antimicrobial activities, phytochemical screening, Uvaria afzelii Scott Elliot, Tetracera alnifolia Will

The Effect of Electrolyte on Dye Sensitized Solar Cells Using Natural Dye from Mango (M. indica L.) Leaf as Sensitizer

Dye-sensitized solar cells (DSSC) were fabricated with mango leaf dye extracts as natural dye sensitizers at pH value of 5.20 and temperature of 18.1˚C. Methanol was used as dye-extracting solvent. DSSCs from dye extract of M. indica L. with KMnO4 electrolyte had the highest photocurrent density of 1.3 mA/cm2 and fill factor FF of 0.46 for the sun at its peak. Potassium permanganate (KMnO4) had a photocurrent density of 1.3 mA/cm2 and FF of 0.8 at sundown. Potassium Iodide (KI), Potassium Bromide (KBr) and Mercury Chloride (HgCl2) electrolytes had 0.2 mA/cm2, 0.08 mA/cm2 and 0.02 mA/cm2 photocurrent densities respectively. The fill factors of 0.09, 0.03 and 0.003 respectively for sun overhead while 0.08 mA/cm2, 0.01 mA/cm2 and 0.01 mA/cm2 were the values of photocurrent densities respectively at sundown. The fill factors were 0.02, 0.0006 and 0.003 respectively at sundown. The maximum power Pmax of the DSSCs were 0.5 mW/cm2, 0.10 mW/cm2, 0.01 mW/cm2 and 0.012 mW/cm2 respectively at 1300 h at 1630 h 0.9 mW/cm2, 0.14 mW/cm2, 0.005 mW/cm2 and 0.0015 mW/cm2 respectively

Stress, coping and job satisfaction in UK academics during the COVID-19 pandemic

Objectives. The occurrence of work-related stress is high among UK academics. This is associated with increased risk of ill-health, reduced productivity, and lower job satisfaction. These might have been exacerbated by the coronavirus disease (COVID-19) pandemic. Social support and coping strategies have the potential to ameliorate the impact of stress but have been less explored in academics; these were explored in a cross-sectional study. Methods. Fifty academic staff were recruited via links posted on social media and through snowballing sample technique. The survey included key demographics such as age, gender, relationship status, educational attainment, known to have relationship with work-related stress. Other measures include perceived stress, social support, coping strategies and job satisfaction. Results. Moderate stress was found in UK academics. Greater impact of COVID-19 and greater use of avoidance coping were significant predictors of higher stress. Conclusion. Encouraging the use of adaptive coping strategies such as problem solving, through staff training could help to reduce stress. Future longitudinal research should examine stress and coping in academics, establishing causation, while accounting for confounders such as contract type, teaching hours, and class sizes. Stress-management interventions should account for pandemic-related stressors including high workload and isolation, as academics continue to engage in hybrid/remote working. Implication. It is important that universities put in place support systems to reduce the level of stress in academics. This could be through training and education in the use of adaptive coping strategies, such as planning and problem solving as well as support from co-workers and management; which are associated with positive psychological wellbeing

Automating consumer's connections to the distribution network for enhanced performance

Abstract:Trial and error approach which involves service interruption is usually carried out to resolve unbalance on phases in power distribution system. This approach might improve the phase voltage and current but the resultant effect (change) does not last for too long; thereby reduces the market value in terms of quality and reliability of supply. To enhance the performance of the secondary distribution system there is a need for an automating technology. The aim of this paper is to introduce a method and technology developed for resolving imbalances in a secondary distribution system as a result of the uneven distribution of single phase load across a three phase power system. The technology developed is able to monitor, acquire/display collected data and perform self changing switching actions electronically. This action is in form of rearrangement or transfer of consumer loads for optimal performance of the distribution feeder. The proposed switching technology is based on open- transition switch that enables transfer or rearrangement of consumer loads in a three-phase system within milliseconds with supervisory control system. The following methodologies: System Simulator - Matlab (Simulink), Virtual Instrumentation-Lab VIEW and Hardware implementation were applied for the validation of the proposed techniqu

Analysis of Independence of Available Infrastructure on Geographical Location of Public Secondary Schools in Ondo State, Nigeria

This paper has attempted to study the availability of infrastructural facilities in public secondary schools in Ondo State, Nigeria. Six local government areas (LGAs) were randomly selected with due consideration to the geo-political set-up of the State. Quantitative methods of analysis that were used include both descriptive and inferential statistics. The descriptive statistical techniques were tabular presentation and bar chart while the inferential statistical technique applied is chi-square analysis. The inferential statistics revealed that enrollment of students in secondary schools depends on gender and on Local Government Area. Also, the level of equipping of laboratories, availability of information technology facilities,  portable water supply and supply of electricity depend on Local Government Area while availability of library in secondary schools is independent of Local Government Area. Conclusively, much still need to be done in the area of infrastructural development in public primary and secondary schools in Ondo State towards the achievement of the vision 20: 2020 goal of Nigeria as one of the 20 most developed economy of the world in terms of education. Keywords:  education, infrastructure, information technology, chi-square, enrollment