Numerical Investigation and Improvement of Aerodynamic Performance of Savonius Wind Turbine

Higher demand for energy has lead to increase in the consumption of conventional energy which has become more expensive and scarce. There is the need to generate power from renewable sources to reduce the demand for fossil fuels and growing concern due to increase in the effects of climate change, such as global warming and acid rain generated by extensive and deliberate use of fossil fuels in the electric generating plants and transport system. In this work, the aerodynamic characteristics of Savonius wind turbine were investigated numerically by varying the rotor configuration (semi-circular and segment of circle) and overlap ratio so as to obtain the optimum design configuration which could give better performance of Savonius rotor. Comparison between the static torque coefficient at different overlap ratios of 0%, 20%, and 40% for the two configurations were studied using Solidworks CFD software. The flow around the rotor with overlap ratio variation was analyzed with the help of velocity, pressure contours and static torque coefficient equation of the rotor. It was observed from the analysis that the overlap of 20% was the optimum overlap condition at which pressure, velocity differences and coefficient of static torque across the rotor were the highest for both configurations and that segment of a circle produced the highest characteristics for better performance. Keywords: Overlap ratio, aerodynamic, Savonius, Static torque coefficient, rotor configuration

Theme: Renewable Energy and Sustainability Experimental and Numerical Study of Drying of Moringa Oleifera Leaves

Drying is a preservation technique to reduce the water content of the food product to a safe level and to minimize biochemical reactions of the degradation and also to increase the shelf life of the product. Moringa being an agricultural product of high chemical, nutritional and medical use is susceptible to degradation due to relatively high moisture content. Moringa leaf is sensitive to sunlight, therefore, forced convection drying method with two types of air velocities (2.2 and 1.2 m/s) was employed in its drying. A batch of moringa leaves of 200g by mass having an initial moisture content of 83% wet basis was dried to desired 14% wet basis  moisture content at average temperature of 40oC. Drying chamber and ambient temperatures, relative humidity, air flow velocity and rate of weight reduction were measured. The experimental and model results were statistically validated. Also numerical modeling of heat and mass transfer that occurred in the drying process was done using COMSOL Multiphysics 4.3b that uses finite element approach. It took between 10 and 12 hours to dry moringa leaves to the desired moisture content at drying air velocity 2.2 m/s and 1.2 m/s respectively. The results predicted from the modelling when compared with the experimental data have a considerably agreement

Sunmonu: Development Of Management Tool And Computerization Of Mechanized Aquacultural Farm Operations

ABSTRACT A management tool for mechanized aquacultural farm operations was developed. The specific operations for mechanized aquaculture farm operations were identified to include; concrete culture/breeding tank design, water quality management, fish record, feed records, feeding, cost simulation, economic analysis of operations and general report on various individual operations. The management tool was a computer programme developed in Visual Basic. The versatility and object oriented capability of Visual Basic was exploited. Appropriate design consideration for concrete culture/breeding tank design was adopted following establishment and standard procedures. Water quality management, feed composition and nutrition requirements were based the minimum acceptable data as recommended for rearing catfish Wayne (2004). Two different sets of production cycle data were obtained from an existing farm, Icon Fishery, Ganmo, Kwara State, Nigeria to validate the programme. The developed management tool was used to stimulate similar production cycle following the prevailing operation condition at Icon Fishery Farm. The result of the actual data from the Icon Fishery show of a profit of N 426,191 in the first data analyzed while in the second data a deficit of N 206,649 was obtained the results of the predicted data also indicated profit of N 485,958 was for the first data analyzed with similar category of data used for the real life data from Icon fishery and a loss of N 70,402 was obtained for the second set of data following the same procedure for the first data analyzed. Data analysis was carried out to determine whether there was a significant difference between observed data results and simulated data results using the method described b

Qualitative Assessment of Effects of Encroachment on Water Resources of Agba Dam, Ilorin Nigeria

The city of Ilorin in Nigeria has experienced high population growth and rapid urbanization. Agba Dam is one of the major sources of potable water in Ilorin, and currently been threatened by anthropogenic induced encroachment activities, with potential for significant derogatory effects on its quality. Therefore, this paper assesses the qualitative impact of encroachment on the water resources regime of Agba Dam, Ilorin, Nigeria. Field survey was carried out to scope proximal anthropogenic activities and to delineate historical and current extent of the encroachment area of the dam. Representative water samples were collected from locations within the dam catchment, and subsequently analyzed for alkalinity, dissolved carbondioxide, chloride, total iron, copper, sulphate, colour, calcium, dissolved oxygen and turbidity. In addition, historical physical and chemical data of water samples obtained from the dam were also acquired, and analyzed to determine temporal variation in the quality. The results show a reduction of 0.89 km2 or 63% in the historical buffer boundary of the dam. The values of the measured physico-chemical parameters were generally similar to that obtained for the historical values and therefore suggest limited impact of the anthropogenic activities on the water quality. However, slight increases were observed in the measured concentrations of the alkalinity, dissolved carbondioxide, chloride, iron, copper and sulphate, and this indicates possibilities of water quality alteration, with potential consequences for ecosystem and aquatic life if the trend is unabated. Keywords: Anthropogenic, Water quality, Agba dam, Ilorin Nigeri

The Use of Fibre Waste as Complement in Concrete for a Sustainable Environment

One of the many challenges faced in developing world is the issue of waste management. Organic fibres forms major percentage of waste produced from agricultural products and should be of great concern. Fibres have been used to reinforce composites concrete to obtain lighter weight, reduce shrinkage effects which serve to reduce environmental waste. Natural fibre is 100% bio-degradable and recyclable, thereby eliminate pollution, promote biodiversity and conservation of natural resources and thus environmentally friendly.This paper focuses on utilization of some fibres as solid wastes for making economically-friendly and affordable green environment. Three fibres: Jute, Oil palm and Polypropylene fibres were used as complement in concrete and its suitability, durability and influence on the properties of concrete were assessed. The percentages of fibre used were 0.25 and 0.5 of cement content by weight. A total of 84 concrete cube specimens were prepared for standard tests which include compression test, slump test and compaction factor test. The compression test was carried out at concrete ages of 7, 14, 21 and 28 days. As the percentage of the fibre increases, the tendency for fibre to ball up becomes higher in water. The test results showed that for Jute and Oil palm fibres, the optimum fibre content was 0.25% and for Polypropylene fibre, the optimum fibre content was 0.5%. They all yielded increase in strength when compared to the control specimen and has proven to reduce reasonable environmental waste pollution. Keywords: Environmental Pollution, Fibre, Concrete strength, Jute, Waste reductio

Stacking tolerance to drought and resistance to a parasitic weed in tropical hybrid maize for enhancing resilience to stress combinations

Open Access JournalMaize is a food security crop cultivated in the African savannas that are vulnerable to the occurrence of drought stress and Striga hermonthica infestation. The co-occurrence of these stresses can severely damage crop growth and productivity of maize. Until recently, maize breeding in International Institute of Tropical Agriculture (IITA) has focused on the development of either drought tolerant or S. hermonthica resistant germplasm using independent screening protocols. The present study was therefore conducted to examine the extent to which maize hybrids simultaneously expressing resistance to S. hermonthica and tolerance to drought (DTSTR) could be developed through sequential selection of parental lines using the two screening protocols. Regional trials involving 77 DTSTR and 22 commercial benchmark hybrids (STR and non-DTSTR) were then conducted under Striga-infested and non-infested conditions, managed drought stress and fully irrigated conditions as well as in multiple rainfed environments for 5 years. The observed yield reductions of 61% under managed drought stress and 23% under Striga-infestation created desirable stress levels leading to the detection of significant differences in grain yield among hybrids at individual stress and non-stress conditions. On average, the DTSTR hybrids out-yielded the STR and non-DTSTR commercial hybrids by 13–19% under managed drought stress and fully irrigated conditions and by −4 to 70% under Striga-infested and non-infested conditions. Among the DTSTR hybrids included in the regional trials, 33 were high yielders with better adaptability across environments under all stressful and non-stressful testing conditions. Twenty-four of the 33 DTSTR hybrids also yielded well across diverse rainfed environments. The genetic correlations of grain yield under managed drought stress with yield under Striga-infestation and multiple rainfed environments were 0.51 and 0.57, respectively. Also, a genetic correlation between yields under Striga-infestation with that recorded in multiple rainfed environments was 0.58. These results suggest that the sequential selection scheme offers an opportunity to accumulate desirable stress-related traits in parents contributing to superior agronomic performance in hybrids across stressful and diverse rainfed field environments that are commonly encountered in the tropical savannas of Africa

MORPHOMETRIC AND MERISTIC STUDY OF ETHMALOSA FIMBRIATA (BOWDICH) FROM BRACKISH WATER AND MARINE ENVIRONMENT

A study of Ethmalosa fimbriata (Bowdich) from Lagos lagoon (brackish water) and Lagos coast (marine environment) using meristic and morphometric characteristics was carried out. Length frequency distribution method was used to separate the sample fish to three age groups. One year old specimens from both the brackish water and marine environments were compared. The total lengths ranged from 9.9cm to 16.0cm. Variations were also studied for one year, two years and three year old specimens in the marine environments. Among the meristic and morphometric characters investigated dorsal rays, anal rays, left gill rakers and right gill rakers showed some differences that were statistically different among the three age groups.  It is therefore concluded that E. fimbriata strains from brackish water and marine environment are genetically inseparable, since environmental factors such as salinity have effect on the migratory habit of the fish.Â

Water Absorption Characteristics of Two Rattan Species (Laccosperma Secundiflorum and Eremospatha Macrocarpa) from Fresh Water Swamp, Lagos State and Rain Forest, Edo State, Nigeria

Water Absorption is one of the properties that determine the suitability of rattan canes as structural material especially for outdoor use. This study therefore evaluated the water absorption characteristics of two rattan species (laccosperma secundiflorum and eremospatha macrocarpa) from a fresh water swamp, Arapagi village, Lagos state and rain forest-Nicholas village, Edo state in Nigeria by collecting three matured wild rattan species from each ecological location and the water absorption carried out after 24 hours and 48 hours respectively. The results show that, water absorption after 24 hours ranged from 39.63 % to 82.51%. However, water absorption after 48hours increased from 44.53 % to 93.74 %. It was also observed that water absorption after 24 hours and 48 hours increased along the axial direction from base to top. Meanwhile, the samples of the two rattan species sourced from Rain forest had lower water absorption values than Fresh water swamp. In conclusion, the two rattan species had different levels of water affinity, however, samples obtained at the base from Rain forest absorbed less water

MEASUREMENT OF MEAN VELOCITY PROFILE IN A TURBULENT PIPE FLOW – A NUMERICAL APPROACH

Computational Fluid Dynamics FLUENT codes were employed in the measurement of the mean velocity profile of a fully-developed pipe flow. The codes used the standard two equation eddy-viscosity () model for analysing turbulence in the flow. Deviations of about 2-12%, 1.1-1.7% and 1.02-5.3% obtained between the numerical results and the experimental benchmark for the study in the viscous sub-layer, buffer region and the fully-developed region of the flow show the close agreements between the experimental and the numerical results

REPRODUCTIVE RESPONSE TO INCLUSION OF GRADED LEVELS OF Ipomoea purpurea LEAF MEAL (MORNING GLORY) IN DIETS OF LAYING CHICKENS

Reproductive responses of laying birds fed Ipomea purpurea leaf meal (IPML) were investigated. Atotal of 40, 25-weeks old birds grouped into four treatments of 0, 2.5, 5.0 and 7.5% inclusion levels of IPML were used for this experiment in a completely randomized design layout. The birds were artificially inseminated with semen from cockerels on controlled diet thrice in a week. A total of 400 eggs were collected and set in an incubator. There were no significant differences (p>0.05) in Hen day production,feed/dozen eggs and the egg characteristics investigated. The blood glucose levels significantly decreased (p<0.05) while level of progesterone significantly increased (p<0.05) with increase inlevel of IPLM inclusion. The percentages of fertility and hatchability were high while the survivability was 100%. It can be concluded that IPLM inclusion level of up to 7.50% supports high fertility, hatchability and survivability and could be used in breeder diets for the production of fertile eggs