174 research outputs found

    Optimization of the Operational Conditions for Cross Flow Turbine Developed for Power Generation

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    In a bid to optimize the performance of a Cross Flow Turbine designed and fabricated by Oyebode (2014), the performance evaluation of the turbine at various conditions was carried out using a portion of the overflow from the University of Ilorin (UNILORIN) dam. The Dam has a net head of 4 m, flow rate of 0.017m3 and hence theoretical hydropower energy of 668W. The turbine was tested and the optimized value of operating conditions namely; angle of inclination of the water jet (15o above tangent, tangential and 15o below tangent), height of water jet to impact point (200mm, 250mm and 300mm) and length of the water jet to impact point (50mm, 100mm and 150mm) were pre-set at their various levels while testing the Turbine. The measured outputs were Turbine Speed, Turbine Torque, Alternator Speed as well as the output voltage. The optimum values of the process output or measured parameters were determined statistically using a 33X2 factorial experiment in three replicates. An optimum turbine speed of 330.09 rpm was achieved by pre-setting 250mm height to impact point, 100mm length to impact point and the water jet 15º below tangent. Same combination also yielded an optimum turbine torque of 39.07kNm. During loading (i.e. when the alternator becomes connected to the turbine), an optimum Turbine Speed of 197.66rpm was achieved by pre-setting 250mm height to impact point, 100mm length to impact point and the water jet 15º below tangent. Same combination also yielded an optimum Turbine Torque of 25.02kNm, optimum Alternator speed of 879.24rpm and an optimum output voltage of 4.05V. The results therefore show that the turbine must be set at these operational conditions for it to perform optimally. Key words: Micro hydropower, Cross Flow turbine, Power generation, Dam overflo

    Development of Hydropower Turbines Powered by Dam Overflow

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    The epileptic power supply in most rural areas in Nigeria and its attendant negative impact on the economy of the Nation, Agricultural productivity and huge rural emigration, is a serious source of concern. This necessitated the development of two hydro-power turbines powered by the overflow (which was rather considered a waste) from University of Ilorin (UNILORIN) dam. A portion of the overflow was channeled into a Polyvinyl Chloride (PVC) pipe and the flow rate was calculated to be 0.017m3/sec using the bucket method. The change in elevation between the overflow and the point of usage was reported to be 4m. The flow (Q) and Head (h) were typical values for many streams and rivers in different rural areas of Nigeria, hence its suitability and adoption for this study. Two turbines viz: Pelton Wheel (PW) and Cross Flow (CF) were developed and tested. The PW generated a speed of 538.4rpm and a torque of 46.2kNm at off load condition while the CF generated a speed of 330.1rpm and a torque of 39.07kNm at the same condition. During loading – when the alternator had been connected to the turbine - the PW turbine speed and torque became 392.0rpm and 36.5kNm respectively, while that of the CF became 197.7rpm and 25.0kNm respectively. A belt and pulley mechanism was used to deliver the rotational speed to the alternator and this increased the alternator speed from the PW and CF turbines to 1768.6rpm and 879.24rpm respectively. The speed from the PW was enough to power the alternator as the alternator only requires 1500rpm to function optimally. The PW was thus adjudged the most suitable for use

    Strategic Approach for Controlling Soil and Groundwater Contamination in Urban and Rural Areas of Nigeria

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    Soil pollution and groundwater contamination are rampant in urban and rural areas of various developing countries including Nigeria. The quality of groundwater is a vivacious concern for human beings since it is directly associated with the human welfare and it is needed to conserve water resources. This paper x-rays strategic approach for controlling soil and groundwater contamination to enhance the efficiency of civil and environmental engineering design through recent trends and practice which will play a vital role in handling environmental pollution. Strategic approach highlighted involves the formulation and implementation of the major goals and initiatives based on consideration of resources and an assessment of the internal and external environments in which the organization competes. One or more of these approaches are often combined for more cost-effective treatment. The field studies for assessment of contamination comprised of detailed hydro-geological investigations which include geophysical investigations, borehole drilling, development of monitoring wells, followed by collection and analysis of existing field samples (dumpsite, subsurface soil and groundwater) are very critical for efficient handling of environmental pollution. It has been concluded that basic necessities for a healthy environment and public health include clean air, safe and sufficient water Safe and adequate food, safe and peaceful settlements, stable global environment in order to achieve excellent public health without soil pollution and groundwater contamination. Strategic approaches to remediation of contaminated soils include isolation, bioremediation, immobilization, toxicity reduction, physical separation and extraction

    EFFECT OF PULSED ELECTRIC FIELD ON STRUCTURAL MODIFICATION AND PHYSICOCHEMICAL PROPERTIES OF STARCH-BASED EDIBLE FILMS

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    Starch-based edible film is a novel packaging material that has gained much recognition and attention in the food industry. Its remarkable functional property like microbial deactivation without posing harmful effect on food materials is remarkable. The application of pulsed electric field (PEF) treatment to starch-based edible film is fundamental to ensuring physicochemical changes and structural modifications of films for the purpose of food safety and handling. However, the effectiveness of PEF is affected by process and product parameters, thus information on the effects of PEF treatment on structural modifications and physicochemical properties of starch-based edible film is useful to the food industry.This review provided an overview of the effects of PEF treatment on structural modifications and physicochemical properties such as density, solubility, water activity (aw) and stability of starch-based edible films. The significance of starch-based edible films to the food industry with a focus on potato, cassava, yam and taro starch sources is summarized. The PEF treatment and factors related to process and product parameters affecting its performance and its effects on structural and physicochemical properties of starch-based edible films were succinctly discussed. PEF treatment can cause microbial deactivation, influence the structural and physicochemical properties and produce edible films with much functionality. The future trends of PEF treatment on starch-based edible films should mainly focus on combining other physical treatment as an integrated way of improving the potentials of PEF towards development of a wider range of functionalized films

    Evidence on physical activity and sedentary behaviour in Ghana: A rapid scoping review

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    In Ghana, more than four in ten deaths in 2016 resulted from non-communicable diseases (NCDs). Physical inactivity and sedentary behaviours are important risk factors for NCDs. No previous systematic reviews examining physical activity and sedentary behaviour among Ghanaians were identified. Therefore, this rapid scoping review was conducted to find and synthesise what is known about the epidemiology of physical activity and sedentary behaviour of children and adults in Ghana. MEDLINE was searched for eligible studies and a narrative synthesis was conducted based on 17 identified papers as well as the 2008 Demographic and Health Survey report. Little recent high-quality data on prevalence of physical activity or sedentary behaviour in Ghana was found. Existing nationally representative data is now more than ten years old. The data identified suggest that the majority of Ghanaian adults, aged 18+ years, are physically active, achieving or exceeding World Health Organisation (WHO) recommendations (84.3% according to data collected in 2007-2008). Studies reporting sedentary behaviour in adults further suggest that the majority of Ghanaians are minimally sedentary. The most consistent associations with physical activity were by gender (men achieved more than women), employment (the employed, particularly in skilled manual jobs, achieved more than the unemployed), urban or rural residence (rural inhabitants achieved more than urban inhabitants) and socio-economic status (lower physical activity with increasing socio-economic status). Meanwhile, the few existing studies of physical activity in children (all of which investigated children aged 12+ years) suggest that the proportion of children achieving WHO recommendations on physical activity may be lower than for adults. A similar gender trend exists for children as in the adult data, with boys achieving more physical activity than girls. Physical activity is accrued most frequently through active travel, and active occupations, while leisure time physical activity is low. This means that the Ghanaian population may be vulnerable to becoming increasingly inactive as work and travel become more frequently mechanised and sedentary.&nbsp

    Cost Implication of Inventory Management in Organised Systems

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    This paper investigates the role of cost implication in inventory management in order to improve Institutions’ Stores. The study takes a critical look at the costs involved and the use of economic order quantity as a tool that minimizes the total inventory costs, the time saved between the manual and the automated operational system using a Nigerian University Store, AYZ University (not the real name because of the ethical issue), as a case study. The study was being guided by the following objectives; to have stocks available when required, to maintain accurate stock records and facilities, and to recommend area improvement of the inventory system at AYZ University Stores. Findings revealed that the economic order quantity is seen as a control technique that is attributed to determine the inventory costs and how it can be minimized. The data collected from the store were analyzed and the results obtained shows that the existing system which is majorly manual based is not effective when it comes to time management and efficiency. A new automated system, computerized maintenance store system (CMMS) was proposed for development and implementation for the AYZ University Store for her end users of the store and her clients from within and outside the University system. This would be greatly improved in terms of both financial and time cost of inventory management

    Meat versus meat alternatives: which is better for the environment and health? A nutritional and environmental analysis of animal-based products compared with their plant-based alternatives.

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    BACKGROUND: Poor diets lead to negative health outcomes, including increased risk of noncommunicable diseases. Food systems, most notably agriculture, contribute to greenhouse gas emissions (GHGE) that lead to climate change. Meat consumption plays a role in both health and environmental burden. Consumption of meat alternatives may reduce these harms. The aim was to compare meat products and their plant-based alternatives on nutritional parameters, GHGE and price to examine if it is feasible and beneficial for policymakers and health professionals to recommend meat alternatives. METHODS: Data on nutritional information and cost for 99 selected products were collected from five UK supermarkets. Estimates for GHGEs for 97 of these products were found through secondary articles. Median values for nutritional value, GHGE (kgCO2 e) and price per 100 g were calculated to allow comparisons between meat products and their alternatives. Mann-Whitney U tests were used to look for significant differences for each nutrient, emissions and price. RESULTS: Meat alternatives contained significantly more fibre and sugar and were significantly higher in price compared to the equivalent meat products. Meat alternatives had a significantly lower number of calories, saturated fat, protein and kgCO2 e than meat products. There was no significant difference in the amount of salt between meat and meat alternatives. CONCLUSIONS: Overall, this paper found that meat alternatives are likely to be better for health according to most parameters, while also being more environmentally friendly, with lower GHGEs. However, the higher price of these products may be a barrier to switching to meat alternatives for the poorest in society

    Evidence on physical activity and sedentary behaviour in Ghana: A rapid scoping review

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    In Ghana, more than four in ten deaths in 2016 resulted from non-communicable diseases (NCDs). Physical inactivity and sedentary behaviours are important risk factors for NCDs. No previous systematic reviews examining physical activity and sedentary behaviour among Ghanaians were identified. Therefore, this rapid scoping review was conducted to find and synthesise what is known about the epidemiology of physical activity and sedentary behaviour of children and adults in Ghana. MEDLINE was searched for eligible studies and a narrative synthesis was conducted based on 17 identified papers as well as the 2008 Demographic and Health Survey report. Little recent high-quality data on prevalence of physical activity or sedentary behaviour in Ghana was found. Existing nationally representative data is now more than ten years old. The data identified suggest that the majority of Ghanaian adults, aged 18+ years, are physically active, achieving or exceeding World Health Organisation (WHO) recommendations (84.3% according to data collected in 2007-2008). Studies reporting sedentary behaviour in adults further suggest that the majority of Ghanaians are minimally sedentary. The most consistent associations with physical activity were by gender (men achieved more than women), employment (the employed, particularly in skilled manual jobs, achieved more than the unemployed), urban or rural residence (rural inhabitants achieved more than urban inhabitants) and socio-economic status (lower physical activity with increasing socio-economic status). Meanwhile, the few existing studies of physical activity in children (all of which investigated children aged 12+ years) suggest that the proportion of children achieving WHO recommendations on physical activity may be lower than for adults. A similar gender trend exists for children as in the adult data, with boys achieving more physical activity than girls. Physical activity is accrued most frequently through active travel, and active occupations, while leisure time physical activity is low. This means that the Ghanaian population may be vulnerable to becoming increasingly inactive as work and travel become more frequently mechanised and sedentary

    Factors for Consideration in a Plan for Terrestrial Oil Disaster Mitigation

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    Oil spills, are common disasters associated with hydrocarbon exploration and production, can be devastating and severely impact water quality, which can be detrimental to human life and the environment. One of the primary objectives of oil spill planning and response, aside from protecting human beings, is to reduce the environmental consequences of spills and cleanup efforts. This objective is best achieved by responders identifying sensitive resources ahead of time to establish protection priorities and select cleanup strategies. When a plan is well situated, within the limited hours available to respond, responders will not have to contact all of the various resource managers for information on essential resources to protect. That means that the effectiveness of the Environmental Sensitivity Index (ESI) map of an area depends on the integral component of overall planning activity. This qualitative study explored and used publicly available and nonproprietary data to mimic the coastal and marine sensitivity representations on emergency preparedness for environmental disaster in terrestrial settings and produce a plan to address such potential disaster. Results indicate that there is a need to classify the resources that society values, such as biological, socioeconomic, or cultural assets, and describe the state of a system and the degree to which a system or asset is affected, either positively or negatively, in the event of an oil spill. Terrestrial Environmental Sensitivity Index mapping will help to support the highest response priorities, prevent impacts to human life, prevent oil from leaching into groundwater or as runoff, and return the environment to productive use as quickly as possible, leading to positive social change

    Methanol fraction of Calliandra portoricensis root bark activates caspases via alteration in mitochondrial viability in vivo

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    Introduction: Dysregulated apoptosis is associated with a number of disease conditions. Traditionally, Calliandra portoricensis is used in the management of prostate enlargement. This study investigates the in vivo effect of potent methanol fraction of C. portoricensis (MFCP) on mitochondrial permeability transition (mPT) pore, an important pharmacological target in treatment of various diseases, and examines the toxicities associated with its oral administration. Methods: Forty-two male Wistar strain rats (70-80 g) were divided into 6 groups of 7 animals each. Each group was orally administered 25, 50, 100, 200, 400 mg/kg MFCP and the control group received distilled water for 21 and 30 days, respectively. mPT, assay for serum enzymes and hematological parameters were assessed spectrophotometrically while activation of caspases 3 and 9 was done by ELISA technique. Histological assessment of vital organs (liver, kidney, prostate) was carried out according to standard procedures. Results: There were no significant effects on mPT pore at all doses administered after 21 days of oral administration. However, after 30 days of administration, MFCP induced mPT pore opening at doses 100 and 200 mg/kg with induction folds of 2.6 and 3.3, respectively while there was no induction of mPT pore opening at lower doses of 25 mg/kg and 50 mg/kg. Furthermore, significant (P < 0.05) increases in serum enzymes (ALT, AST) were observed at all doses administered when compared with control after 30 days of oral administration. Cell counts (Hb, PCV, RBC, WBC) were adversely affected at the highest dose (200 mg/kg) compared with control and other treated groups (25, 50 and 100 mg/kg) after 30 days of administration. Similarly, activation of caspases 9 and 3 were observed in rat liver homogenate at high doses of the fraction while histological evaluation showed degeneration and distortion of organs at the highest dose. Conclusion: MFCP contains phytochemicals that elicit the opening of the pore and induction of mitochondrial-mediated apoptosis. This would be relevant in treatment of degenerative diseases that results from down-regulation of apoptosis. However, caution should be exercised in using high doses of the plant
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