17 research outputs found
Evaluation of Physicochemical Properties of Sachet Water Quality Vended Along Song-Gombi Route, Adamawa State, Northeastern Nigeria
Get PDFPeople need safe drinking water to survive; hence, the quality of drinking water is crucial. Nigerians' ambition to consume sachet water has made it possible to analyse the quality of various sachet water brands, hence, the objective of this paper was to evaluate the physiochemical properties of sachet water quality vended along Song-Gombi Route, Adamawa State, Northeastern Nigeria using appropriate standard methods by collecting 10 brands of sachet water labeled 1-10. The pH readings of all 10 different brands of sachet water, which ranged from 6.75 to 7.91, were within the allowable limit. The allowed limit was met by the turbidity result, which ranged from 0.32 to 4.90 NTU, and the TDS, which ranged from 0.00 to54.00 mg/L. There was a range of 31-340C, 131-202µS/cm, and 23.99-71.98 mg/L for temperature, conductivity, and chloride, respectively. Atomic Absorption Spectroscopy (AAS) Buck Scientific VPG, 210 model was used to determine the concentrations of Pb, Cu, Mn, Mg, and Cd. With the exception of Mn, which was found in two brands of sachet water, sample 8 (0.60 mg/L) and sample 10 (0.84 mg/L), the findings of the metal concentration tests were below the WHO/SON acceptable limit. None of the samples had any Pb. These findings indicate that high quality standards must be followed. Additionally, evaluating market samples at random will be an effective method for determining whether the quality meets the necessary requirements
Design and development of solar still for effectiveness in eliminating microbial contamination and salt in Mubi, Adamawa State, Nigeria
No full textSolar still for the production of clean quality water fit for human consumption and other hygienic uses has been designed and developed. The design and operation, which is based on energy and environmental physics concept of rainwater-evaporation and condensation process, is simple, straightforward and has low maintenance cost. Twenty-four water samples were collected from various boreholes in Mubi, Adamawa State, Nigeria, in sterile bottles. Enumerations of aerobic bacteria by aerobic plate count and coli form by multiple-tube fermentation technique have been carried out. Results showed that heavily contaminated samples with an average microbial load of 2.57x10cfu/ml; a positive 100% distribution of coli form bacteria; and an input average of 266.7mg/l of CaCO were completely eliminated producing up to 9 litres of pure water, with an average pH value of 9.13 per day in temperate climate. The water does not acquire the \'flat\' taste of commercially distilled water since it is not boiled. This study is therefore an application of physics for the production of distilled water from contaminated water for both human health protection and environmental sustainability. Keywords:Solar still, portable water, health protection. Nigerian Journal of Physics Vol. 18 (2) 2006: pp. 203-21
Design and development of solar still for effectiveness in eliminating microbial contamination and salt in Mubi, Adamawa State, Nigeria
No full textMaximum Power Point Tracking in Partial Shaded Photovoltaic System using Smell Agent Optimization Algorithm
Get PDFWith partial shading conditions, it is essential to acquire Maximum Power Point at which the Photovoltaic systems (PV) operate effectively despite the variation in the cell temperature and incident angle of sunlight rays on the panels. This study explores the use of a Smell Agent Optimization (SAO) algorithm for Maximum Power Point Tracking (MPPT) in partial shaded PV systems. The proposed MPPT system is composed of a PV model, a DC-DC converter model and a control part. The Smell Agent Algorithm (SAA) was adopted in the control part of the MPPT system to implement the optimization algorithm using four different shading patterns (SPs) and to calculate the optimal switching duty cycle of the DC-DC converter. The effectiveness of the proposed system was verified using simulations in the MATLAB/Simulink environment. The SAO respectively track maximum values for Power, Voltage and Current as 845.8476 W, 211.7308 V, 3.99492 A while the maximum values for Power, Voltage and Current for Perturb and Observe (P and O) are 845.0465 W, 211.6305 V, 3.993028 A respectively during SP1. The results showed that the SAO algorithm has excellent tracking results in terms of convergence speed, accuracy, power extracted stability, and dynamic response in reaching the optimum point
Maximum Power Point Tracking in Partial Shaded Photovoltaic System using Smell Agent Optimization Algorithm
No full textWith partial shading conditions, it is essential to acquire Maximum Power Point at which the Photovoltaic systems (PV) operate effectively despite the variation in the cell temperature and incident angle of sunlight rays on the panels. This study explores the use of a Smell Agent Optimization (SAO) algorithm for Maximum Power Point Tracking (MPPT) in partial shaded PV systems. The proposed MPPT system is composed of a PV model, a DC-DC converter model and a control part. The Smell Agent Algorithm (SAA) was adopted in the control part of the MPPT system to implement the optimization algorithm using four different shading patterns (SPs) and to calculate the optimal switching duty cycle of the DC-DC converter. The effectiveness of the proposed system was verified using simulations in the MATLAB/Simulink environment. The SAO respectively track maximum values for Power, Voltage and Current as 845.8476 W, 211.7308 V, 3.99492 A while the maximum values for Power, Voltage and Current for Perturb and Observe (P and O) are 845.0465 W, 211.6305 V, 3.993028 A respectively during SP1. The results showed that the SAO algorithm has excellent tracking results in terms of convergence speed, accuracy, power extracted stability, and dynamic response in reaching the optimum point
Phytochemicals and Effect of Blanching Time on Oxalate and Phytate Content in Leaves of Some Non-conventional Vegetables in Gombi Local Government Area, Adamawa State, Nigeria
Get PDFThe objective of this paper was to evaluate the phytochemicals and effect of blanching time on oxalate and phytate content in leaves of some non-conventional vegetables in Gombi Local Government Area, Adamawa State, Nigeria using appropriate standard methods. Data obtained reveals the presence of flavonoids, phenols, steroids and alkaloids in the vegetables. Saponins were found in bitter leaf, kenaf leaf and roselle leaf but absent in moringa and cassia tora leaf. The highest amount of oxalate was present in roselle leaves (17.10±2.30 mg/100 g), followed by moringa leaves (12.30±1.30 mg/100 g), and spinach (10.00±0.85 mg/100 g) of the unblanched samples. The greatest decrease in oxalate concentrations was observed in vegetable samples that were blanched for six minutes. As the blanching time increased, the phytate contents of the vegetables under study decreased. High levels of phytate were detected in unblanched samples of spinach (22.20±1.10 mg/100 g), kenaf leaves (22.00±1.10 mg/100 g), and roselle leaves (22.00±1.80 mg/100 g). In terms of phytate and oxalate content, the concentrations in the examined veggies were found to be within the allowable limit of 25 mg/100 g. All six vegetable samples had flavonoids, phenols, steroids, and alkaloids, according to the phytochemical screening. The hazards of exposure to oxalate and phytate contents can be decreased by changing dietary practices, and the blanching duration of vegetables that are frequently consumed should be continuously monitored for oxalate and phytate content
Anti-microbial and Phytochemical Characterization of Leaves Extracts of Starburr (A. hispidum) collected from Jos North Local Government Area of Plateau State, Nigeria
Get PDFStarburr (Acanthospermum hispidum) extract has been reportedly used in North and Western Nigeria and Nigeria at large to treat stomach ache, malaria and abdominal pain. In view of its usage, the objective of this paper was to characterize, carry out the anti-microbial activity and qualitative and quantitative phytochemical analysis of leaves extracts of Starburr of A. hispidum collected from Jos North Local Government Area of Plateau State. Fine powdered sample of A hispidum leaves were extracted using n-Hexane, acetone, ethyl acetate and methanol sequentially in the increasing order of polarity using maceration extraction method. Percentage yield of the leaves of A hispidum. extracts were n-hexane (3.6 %) acetone (4.0 %) ethyl acetate (2.2 %) and methanol (4.10 %). Qualitative phytochemical screening revealed the presence of alkaloids, tannins, saponins, flavonoids, glycosides and terpenoids. Quantitative phytochemical screening revealed alkaloids (1.456) saponins (3.56) tannins (0.04852) terpenoids(0.05208) for methanol extract alkaloids(1.176) saponins(3.64) tannins(0.0372) terpenoids(0.0398) for ethyl acetate extract and alkaloids(0.328) saponins(3.20) tannins(0.02344) terpenoids(0.01948) for acetone extract. Antimicrobial activity analysis revealed inhibition growth of clinical pathogens which are E. coli, S. aureus, S. typhi, P. aeruginosa, S. pneumonaie, C. albicans as compared with standard of penicillin with inhibition zone of 18 mm and ketokonazol with inhibition zone of 24 mm . The methanol extract with zone of inhibition range of 10 mm to 18.5 mm of the leaves showed a promising potency against the test microbes
Student oral presentations: incorporating peer e-assessment
No full textThis presentation details how an approach to the development of presentation skills with first year accountancy students has been developed to incorporate peer assessment. Presentation skills are considered important by both recruiters and academic bodies (Stowe, 2010) but despite this, accountancy graduates tend to have “inadequate oral communication skills” when commencing employment (Gray, 2010). In order to help the students develop their skills and confidence in delivering presentations, Accountants in Organisations, a first year core module taken by BA Accountancy and Finance students at the University of Huddersfield, has long included two formative presentations and an end of year summative presentation. The formative feedback provided in the first two presentations originally came from the tutor while peers participated only as an audience. The final summative assessment was presented only to the two module tutors.
In order to raise involvement, extend student assessment skills and increase formative feedback, peer assessment was incorporated in the process. Involving peers in the assessment of presentations supports the development of judgement and can improve reliability (Magin and Helmore, 2001). Such an approach also provides peers with a clear purpose during the presentation and may therefore lead to greater interest and participation (MacAlpine, 1999).
The use of e-assessment facilitates the rapid provision of written feedback; an attribute valued by students (Browne and Shurville, 2007; NUS, 2010). Whereas, previously presenters had one set of feedback provided by the tutor, they now have extensive feedback from the whole audience which requires little administration
The Value of Cooperation: Studies on the Performance Outcomes of Interorganizational Alliances.
Get PDFStrategic alliances have gradually emerged over the last decades as a primary vehicle for corporate growth. Firms increasingly use strategic alliances to enter new markets, develop new products and obtain access to relevant knowledge and technological capabilities. Hoewever, while alliances can promote growth and create value they can also destroy it. The prevalence of alliances coupled with the considerable variation in their success rates has led to an increased effort by both scholars and practitioners to find out whether firms benefit from emerging alliances and what makes for a succesful alliance. Yet, despite the large number of studies conducted to date, past empirical research provides no consensus on (a) whether on average, firms benefit from entering alliances, (b) why some alliances create more firm value than others, and (c) the determinants of the performance of alliances themselves. Research presented in this dissertation uses meta-analysis to address these questions and obtain firm empirical generalizations on the performance outcomes of strategic alliances.
Foreign Direct Investment and Trade in the Southern African Development Community
Get PDFWe use a modified gravity model to estimate the relationship between trade and foreign direct investment (FDI) in the Southern African Development Community (SADC). We find evidence of a significant causal relationship from SADC?s exports to inward FDI. Distance (reflecting remoteness and transport costs) and political instability are confirmed to be significant determinants of FDI to SADC. We discern differences in the patterns and determinants of FDI to SADC, whether it is from the USA and UK or from continental Europe. In the case of FDI to SADC from the USA and UK, it is exports from SADC to these countries that are significant, and not imports, while, in the case of continental Europe, both exports and imports are significantly associated with FDI to SADC.FDI, SADC, South Africa, exports, gravity model
