FUOYE Journal of Engineering and Technology (FUOYEJET - Federal University Oye-Ekiti)
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Development of an Anaerobic Digester for Animal Waste
Get PDFAdvancement in biotechnology and bioengineering has provided ways that resources, which hitherto were classified as wastes, now form the basis for energy production. Anaerobic digestion is a highly promising technology used for processing biomass materials (crop residue, human excreta, animal waste and food) in the absence of oxygen to a methane-rich biogas. This work developed a small-scale anaerobic digester to produce biogas from animal waste. The anaerobic digester consisted of three major components: bioreactor with an incorporated stirrer driven by an electric motor, gas scrubber and gas collector. Batch feeding operation was adopted while pig waste was used as test material. Lime water was used as a scrubbing medium for methane enrichment. Loading result revealed that there was seven days delay in gas production from day of loading. The daily temperatures and pH recorded for a period of 50 days were in the range of 29 - 34°C and 5.5 - 7.5 respectively, and the average yield of clean biogas was 0.13 l/kg of slurry/day. Biogas generation increased with days in digester and was a two-stage process with a peak production day between 40 and 45 days. There was observed reduction in carbon dioxide content and methane enrichment as the days increased confirming the effectiveness of the scrubber. The biogas produced comprised between 55.1 and 74.1% of methane, and a range of 22.5 to 38.2% of carbon dioxide and was combustible after the 10th day of digestion. The results obtained showed the overall functionability of the developed anaerobic digester. The digester could be deployed and adopted in farmsteads as well as household to meet their energy deman
PWM Inverter Drive for Modified Single Phase Induction Motors
Get PDFThis paper starts to look at the single phase induction machine which is a large consumer of domestic power supply with the goal of improving its operation. The existing capacitor-run single phase induction motor exhibits a significant level of torque pulsations during starting time and at steady state. This situation gives rise to noise and vibration in the machine. As part of efforts to mitigate these problems, an open loop two phase inverter drive strategy was developed and implemented in MATLAB/Simulink to reduce undesirable pulsations. Simulation results clearly show the superiority of motor performance under the proposed strategy when compared to motor performance under nominal power supply. Torque pulsations are eliminated at steady state with the consequence of reduced noise and heat loss to the environment. The motor is observed to develop significantly higher starting torque and its reliability is significantly increased as the strategy eliminates the need for capacitors and centrifugal switch associated with these motors
Some Later Ages Structural Characteristics of Concrete Containing Empty Palm Oil Fruit Brunch Ash (EPO-FBA) as Partial Replacement of Ordinary Portland Cement
Get PDFThis paper presents the results of the investigation conducted to assess the latter day strengths of concrete in which the cement constituent of the mix has been partially replaced by empty palm oil fruit brunch (EPO-FBA). The structural parameters investigated were: workability, density and compressive strength. Some physical properties and chemical analysis were conducted. Slump test was used to assess the workability, while 150 x 150 x 150mm concrete cube specimens were used to assess the density and compressive strength characteristics. Replacement of Portland cement with EPO-FBA were carried out up to 20% by weight at interval of 5%. The results showed that (i) the concrete specimens with EPO-FBA became less workable with increase in the cement replacement with EPO-FBA, (ii) normal density concrete was obtained with densities in the range 2240 – 2480 kg/m3 when the cement constituent of the mix was partially replaced with EPO-EBA up to 20%, and (iii) the compressive strength developed by the concrete specimens at 5% cement replacement with EPO-FBA was better than the control sample
Assessment of Catfish Effluents Management in Lagos State, Nigeria
Get PDFCatfish is one of the major sources of dietary protein in Nigeria. Lagos State is one of culturing areas with abundant fresh water and marine environments. The aim of this study was to evaluate the catfish rearing industry and its effluents management and make appropriate recommendations. Forty fish farms were randomly selected in Lagos State for the study. Questionnaire and in-depth interview were used for data collection on water sources, equipment operations, and waste management. Data collected were analyzed using descriptive statistics. Results indicated that over 80% of water for fish rearing was from shallow wells and 95% of the waste water generated was not treated before disposal into the environment. Effluents disposals employed were open pit (12.5%), drainage canal (32.5%), bare-land (20.0%), stream (22.5%) and re-used on farm (12.5%) and these methods of disposal were not significantly different (p ≤ 0.05). Only a few farmers carried out simple treatment before disposal namely; infiltration (2.5%) and sedimentation (2.5%). If the effluent management conditions were not improved, it could pose a threat to the environment in the study areas. Pond effluent must be treated before being disposed into the environment and waste water from fish pond effluent should be reused as irrigation water
Statistical Evaluation of Emerging Feature Extraction Techniques for Aging-Invariant Face Recognition Systems
Get PDFLarge variation in facial appearances of the same individual makes most baseline Aging-Invariant Face Recognition Systems (AI-FRS) suffer from high automatic misclassification of faces. However, some Aging-Invariant Feature Extraction Techniques (AI-FET) for AI-FRS are emerging to help achieve good recognition results when compared to some baseline transformations in conditions with large amount of variations in facial texture and shape. However, the performance results of these AI-FET need to be further investigated statistically to avoid being misled. Statistical significance test can be used to logically justify such performance claims. The statistical significance test would serve as a decision rule to determine the degree of acceptability of the probability to make a wrong decision should such performance claims be found faulty. In this paper, the means between the quantitative results of emerging AI-FET (Histogram of Gradient (HoG), Principal Component Analysis-Linear Discriminant Analysis (PCA-LDA) and Local Binary Pattern-Gabor Wavelet Transform (LBP-GWT)) and the baseline aging-invariant techniques (Local Binary Pattern (LBP) and Gabor Wavelet Transform (GWT)) were computed and compared to determine if those means are statistically significantly different from each other using one-way Analysis of Variance (ANOVA). The ANOVA results obtained at 0.05 critical significance level indicate that the results of the emerging AI-FET techniques are not statistically significantly different from those of baseline techniques because the F-critical value was found to be greater than the value of the calculated F-statistics in all the evaluations conducted
Effects of Elevated Temperature on Splitting Tensile Strength of OPC and BLA Pozzolanic Concrete and Mortar
Get PDFConcrete is one of the most common and widely applied construction materials in the world. It is good in compression but weak in tension. The weakness in tension is been catered for through the use of reinforcement but there is still need to ensure that its minimum tensile strength is retained during the course of production and usage to avoid cracks development at the reinforcement cover. Concrete mixes of 1:2:4 (cement: sand: granite) and mortar of 1:6 mix ratio of cement to sand were produced. The ordinary Portland cement (OPC) content was partially replaced with bamboo leaf ash (BLA) from 0% to 12% at 2% interval. They were tested under normal and elevated temperature to know the effect of elevated temperature on their splitting tensile strength. The results obtained showed OPC concrete mix to improve in splitting tensile strength (3.5 N/mm2 to 3.7 N/mm2 at 28 days curing) whereas there was a decrease in the splitting tensile strength obtained for BLA mixes (3.29 N/mm2 to 1.75 N/mm2 for 12% percentage replacement at 28 days curing). The same trend of results was obtained for mortar mix; OPC mix increases from 1.65 N/mm2 to 1.86 N/mm2 while BLA at 12 % percentage replacement decreases from 2.02 N/mm2 to 1.7 N/mm2. OPC concrete and mortar under high elevated temperature (100oC) will improve in splitting tensile strength while elevated temperature decreases the splitting tensile of BLA concrete and mortar mixes at 12%
Determination of Selected Moisture -Dependent Physical and Frictional Properties of Shelled Egusi Melon (Citrullus lanatus Thunb.)
Get PDFPhysical and frictional properties were determined for shelled (i.e. hulled) seeds of egusi melon (Citrullus lanatus Thunb) at moisture content levels of 11.04, 15.7, 21.03 and 24.78 % dry basis. The physical properties investigated were true density, bulk density and the angle of repose; while the frictional properties were the coefficient of static friction and the coefficient of internal friction. Densities were determined using the volume displacement method, while the bulk porosity was calculated as a function of the true and bulk densities. The angle of repose was measured using the cylinder method. The coefficient of static friction of melon seeds on the surfaces of plywood, galvanized iron and glass was determined by sliding a cell filled with the seeds on a tilting table overlaid with the test material surfaces. The coefficient and internal angle of friction were determined by means of a shear test apparatus. Within the range of moisture investigated, the true density of shelled melon seeds decreased from 1,264 to 1,239 kg/m3 while its bulk density increased from 668 to 681 kg/m3. The porosity decreased from 47.19 to 45.36 % while the angle of repose increased from 31.0 to 34.9°. The coefficient of friction of shelled melon seeds on the surfaces of glass, galvanised iron and plywood increased from 0.329 to 0.475, 0.364 to 0.476 and 0.408 to 0.559 respectively. The coefficient and angle of internal friction increased from 0.638 to 0.668 and 32.52 to 33.74°, respectively. These findings are valuable data for efficient design of machines for processing, handling and storage of hulled seeds of egusi melon
Seismic Refraction and Electrical Resistivity Investigation of Building Failure: A Case Study
Get PDFGeophysical methods involving electrical resistivity and seismic refraction were adopted to investigate the cause(s) of failure of main library complex of the Olabisi Onabanjo University, Ago-Iwoye, South-Western Nigeria. The geoelectric section generated from geosounding data revealed four geologic layers. The topsoil has resistivity values varying from 128Ωm to 220Ωm and thickness between 0.9m and 2.4m. The second layer is composed of lateritic clay with resistivity values varying from 238Ωm to 410Ωm and thickness between 2.5m and 5m. The third layer is composed of weathered basement with resistivity values ranging from 56Ω-m to 88Ω-m with thickness between 9.1m and 13.5m. The fourth layer is fresh basement with resistivity values between 1110Ωm and 1200Ωm. The depth to the rock head is between 14.1m and 18.6m. The 2-D subsurface imaging revealed that the foundation soil is composed of clayey materials with resistivity values ranging from 4.3Ωm to 80Ωm, between 0.7m to 5m which correlate well with the geoelectric section. The geovelocity layers’ characteristics substantiate the electrical resistivity imaging and vertical electrical sounding results as it revealed a 4-layer model namely: topsoil, laterite and basement bedrock as the weathered layer is blinded. The topsoil has average velocity 486m/s which is diagnostic of weak/unconsolidated materials presumably clayey materials and average thickness of 2.2m. The sub-weathering/ laterite has average velocity of 1506m/s and average thickness of 7m. The third layer is the bedrock with average velocity of 2292m/s and characterized with a displaced parallel time segment indicating fault within the bedrock. Geotechnical analysis of the subsoil sample revealed that the soils have plasticity index and strength values that are typical of clay. From the result, the building failure observed as cracks and foundation subsidence may have been caused by incompetent foundation soils. It is noteworthy that such faulted zone delineated within the bedrock is also inimical to the building foundation
A Step Block Algorithm for Solving First Order Initial Value Problems in Ordinary Differential Equations
Get PDFThe implementation of the newly formulated polynomials, ADEM-B orthogonal polynomials, valid in the interval [-1, 1] with respect to weight function is our major focus in this work. The polynomials, which serve as basis function are employed to develop finite difference methods. Varying off-step points are considered for only One-Step method for the solution of the initial value problems of Ordinary Differential Equations (ODEs). By selection of points for both interpolation and collocation, threeimportant class of block finite difference methods are produced. The methods are analyzed for their basic properties and findings show that they are accurate and convergent
Assessment of Environmental Impacts of Quarry Operation in Ogun State, Nigeria
Get PDFThe study investigated the environmental effects of quarry operations in Abeokuta, Ogun state, while it specifically sought to identify corresponding environmental impacts posed in quarry operation and, assess the efforts towards minimizing environmental impacts of their operations. Primary data used for this study was obtained from 100 residents of the community and staffs of the company, randomly chosen and administered with structured questionnaires. Ninety one percent of the respondents noted that environmental problems like land degradation and pollution (including air, water and noise pollution) are associated with mining activities in their respective communities. Air pollution and noise pollution were found to have significant (p < 0.05). Long period (58.0%) of surface mining (71.7%) is prominent in the study area, while it posed some hazards to residents in the study area (84.0%). This includes (degradation of land and vegetation (72.0%), water pollution (44.0%), air pollution (44.0%) and noise pollution (56.0%). Noise and air pollution and governmental intervention in environmental degradation of Mining were found to have significant (p < 0.05) impact on host community as identified by staff of mine and residents. Efforts towards minimizing environmental impacts of quarrying include resettlement and compensation of affected communities (20%). Environmental effects such as land degradation and pollution of various forms (air, ground vibration and noise) in the surrounding communities where the mining activities (quarry operations) are carried out are associated with surface mining activities. It is therefore recommended that government agencies overseeing mining operations revise environmental management policy to ensure that the environmental effects of mining activities are reduced to the barest minimum