Sludge is water that contains suspended solids from the source water and the reaction products of chemicals added in the treatment process. And in order to treat and dispose of the solids produced from treatment plants in the most effective manner, it is important to know the characteristics of the solids that will be processed. This study is an investigation into the engineering and chemical properties of sludge collected from different water treatment plants in South-Western Nigeria. After determining the engineering and physical properties of the sludge samples, the sludge samples were also subjected to XRF analysis. It was found out that the sludge which was an alkaline silty-sandy material possessed four major oxides present in a Portland cement which include those of Lime (CaO), Silica (SiO2), Alumina (Al2O3) and Iron (Fe2O3) were also present at an appreciable quantity in the sludge ashes and this feature suggests a possible application of the sludge ash in place of cement only that the sludge remained a non-plastic material.
The quest for valorization of wastes in civil engineering has become prevalent in recent times. This study is an investigation into the potential use of recycled plastics (high density polyethylene) in the production of interlocking paving stones. After batching, 1:3:6 mix of concrete interlocking paving stones was produced in varying recycled plastics proportions of 5%, 10% and 20% as partial replacement for fine aggregates. The stones were moulded in plastic molds of size 220mm X 140mm X 60mm. It was seen that the compressive strength of the RHDPE-concrete interlocking stones at 28days of curing decreases linearly from 20.31MPa (for conventional concrete interlocking stones) to 11.37MPa (for 20% recycled plastics content) and statistically there are significant differences between the compressive strength values obtained for the interlocking stones. Concrete of 5% RHDPE content can be used in lightweight concrete and as interlocking paving stones in walkways only as it is not advisably recommended for car parks and other structural purposes as it tends to fail under heavy load.
This research focused on characterizing the raw, beneficiated and treated Nigerian bentonitic clays using Fourier Transform Infrared Spectroscopy (FTIR) with the aim of determining their mineralogical compositions for application in oil and gas drilling fluid formulation. The frequencies of absorption for all the samples in which the AIAIOH stretching band typically occurs at approximately between 3620-3630 cm-1 and for bending band is situated at approximate values of 920-930 cm-1 which indicates that all the studied bentonite samples are Al-rich montmorillonite of smectite group. The samples also showed small CO3- stretching band at approximately 1430 cm-1 indicating the presence of carbonate impurities.
An assessment of palm kernel processing and storage in South-Eastern Nigeria was carried out by investigative survey approach. The survey basically ascertained the extent of mechanization applicable in the area to enable the palm kernel processors and agricultural policy makers, device the modalities for improving palm kernel processing in the area. According to the results obtained from the study, in Abia state, 85% of the respondents use mechanical method while 15% use manual method in cracking their kernels. In Imo state, 83% of the processors use mechanical method while 17% use manual method. In Enugu and Ebonyi state, 70% and 50% of the processors respectively use mechanical method. It is only in Anambra state that greater number of the processors (50%) use manual method while 45% use mechanical means. It is observable from the results that palm kernel oil extraction has not received much attention in mechanization. The ANOVA of the palm kernel oil extraction technique in South- East Nigeria showed significant difference in both the study area and oil extraction techniques at 5% level of probability. Results further revealed that in Abia State, 70% of the processors use complete fractional process in refining the palm kernel oil; 25% and 5% respectively use incomplete fractional process and zero refining process. In Anambra, 60% of the processors use complete fractional process and 40% use incomplete fractional process. Zero refining method is not applicable in Anambra state. In Enugu sate, 53% use complete fractional process while 25% and 22% respectively use zero refining and incomplete fractional process in refining the palm kernel oil. Imo state, mostly use complete fractional process (85%) in refining palm kernel oil. About 10% use zero refining method while 5% of the processors use incomplete fractional process. Plastic containers and metal drums are dominantly used in most areas in south-east Nigeria for the storage of palm kernel oil.
The field performances of agricultural field machineries in South -East agricultural zone of Nigeria were assessed, to enable farmers and agriculturists select suitable farm machines/implements based on soil conditions/characteristics for their agricultural activities. The various implements studied include; disc plough, 2-gang tandem disc harrow, ridger, rotovator and 6-row combine seed planter. Three different makes and models of tractors namely: New Holland (model-NH5610SE and capacity-55.9kw), Massey Ferguson (model-MF430E and capacity-55.2kw) and Mahindra (model-NH7570E and capacity-55.9kw) with 3- point hitch systems and average age of 1.3 years were used to study the field performances of each of the implements, in five different states that made up the study area. The field performances studied include; implement’s working speed, operation time, depth of cut, effective and theoretical field capacities, field efficiency, fuel consumption rate, implement power requirements, and wheel slippage, under different soil conditions. Results obtained revealed that the disc plough had field efficiency range of 85.74% to 88.55%, effective and theoretical field capacities range of 0.846 to 1.164ha/hr and 0.961 to 1.319ha/hr respectively; and the highest field (ploughing) efficiency was obtained in loamy-sandy soil when the plough was operated with the Massey Ferguson tractor. Harrow recorded field efficiency range of 80.17 to 91.38%, effective and theoretical field capacities range of 0.931 to 1.458ha/hr and 1.151 to 1.667 ha/hr respectively; and the highest field (harrowing) efficiency was obtained on sandy-clay soil by New Holland tractor. Ridger recorded 83.65 to 88.82% field efficiency, 0.932 to 1.322ha/hr effective capacity and 1.073 to 1.504ha/hr theoretical field capacity; and sandy-clay gave the highest field (ridging) efficiency when operated with a New Holland tractor. The rotovator had field efficiency range of 81.10 to 89.81%, effective and theoretical field capacities range of 0.759 to 0.902ha/hr and 0.758 to1.039ha/hr respectively; and the highest pulverizing efficiency was achieved on the clay-loam soil with a Massey Ferguson tractor. The planter recorded 80.63 to 89.37 field efficiency,1.012 to1.481ha/hr effective field capacity and theoretical field capacity of 1.22 to 1.716ha/hr. Ploughing gave the highest average fuel consumption rate of 22.72L/ha (8.89L/hr), followed by harrowing with average consumption of 19.57L/ha (8.04L/hr), ridging recorded 19.42L/ha (7.97L/hr), rotovator had 16.79L/ha (7.19L/hr) and least was planter with average consumption rate of 15.10L/ha (6.26L/hr). More so, all implements recorded highest tyre slippage in sandy-clay soil, followed by loamy-sandy and the least slippage was recorded in the clay-loam soil. Results finally revealed that the highest draft force (10.8kN/m) was obtained by the plough, followed by the harrow and ridger with equal draft force values of 10.5kN/m respectively and least draft was recorded by the rotovator (5.1kN/m).
Physical and aerodynamic properties of African breadfruit (Treculia africana) seeds were studied at four moisture levels: 12.50, 15.00, 17.50 and 20.10% dry base (w.b). As moisture content increased from 10.50 to 20.10% (w.b), the average weight, major diameter, minor diameter, intermediate diameter, geometric mean diameter, arithmetic mean diameter of the seeds ranged from 0.35±0.08 to 0.60g±0.04g, 8.08±0.90 to 10.05±0.60mm, 4.04±0.53 to 5.00±0.10mm, 2.96±0.43 to 4.60±0.40mm, 4.52±0.45 to 6.03±0.20mm, 5.03±0.45 to 6.55±0.50mm respectively. Also the equivalent diameter, surface area, sphericity, projected area and aspect ratio of the seeds ranged from 4.75±0.42 to 6.03±0.41mm, 64.19±12.64 to 114.25±10.00mm2, 56±8.00 to 60±6.00%, 25.64±5.10 to 39.47 ± 3.80mm2, and 50±0.08 to 50±0.01mm respectively. The volume ranged from 0.35 ± 0.014 to 0.73 ± 0.014cm3, while the true and bulk densities ranged from 1.099 ± 0.141 to 1.110±0.424g/cm3 and 0.835±0.43 to 0.938±0.21g/cm3. Porosity decreased from 15.01±1.5 to 5.60±0.4% as moisture content increased from 10.50 to 20.10% (w.b). The angle of repose ranged from 39.80 to 60.10o with increase in moisture content. The optimum parboiling time, temperature and moisture content for hulling African breadfruit seeds were determined as 7.5minutes, 57.5oC and 20.10% (w.b) respectively. The terminal velocity of the seeds and kernels ranged from 12.5 to 17.02m/s and 11.40 to 13.36m/s. Drag coefficient and drag force of the hulls ranged from 0.1 to 0.7 and 0.518×10-4 to 0.858 ×10-4N, while the drag coefficient and drag force of the seeds and kernels ranged from 0.09 to 0.2, 4.50 ×10-4 to 6.00×10-4N; 0.2 to 0.3 and 4.0×10-4 to 5.10×10-4N respectively. This indicates that optimum separation can be achieved effectively without any loss of the seeds if the results obtained are properly applied in processing of African breadfruit.
Selected physical and mechanical properties of horse eye bean (mucuna sloanei) were studied at different moisture content levels of 11.5%, 13% and 17% (db). Compression strength characteristics were conducted under quasi-static compressive force at longitudinal and latitudinal (lateral) loading positions and the rupture forces, compressive strength, modulus of deformability, toughness, stiffness and force at bio-yield point determined as the mechanical properties. Results indicated that volume (20.137 - 21.856 mm3), surface area (598.362 - 720.208 mm2), geometric mean diameter (24.98 - 27.12 mm), and weight (7.625 - 9.203 g) of the velvet bean seed increased linearly with increase in moisture content. Also, the bulk density, specific gravity (0.378 - 0.421 g/mm3), sphericity (0.882 - 0.831) and aspect ratio (0.974 - 0.726) decreased linearly with increase in moisture content. These indicate that Velvet beans have wide size ranges and no single sample of the grains can effectively represent the other. In the case of the force-deformation characteristics, result indicates that the force and corresponding deformation to rupture of velvet bean seeds were found to vary from 400N - 2500N and 3mm - 10.25mm in longitudinal loading positions and 800N - 2800N, 3.5mm - 11.5mm in lateral loading positions at the various moisture contents. The bio-yield force, compressive strength, stiffness and toughness of the velvet bean seeds varied from 400N - 1000N, 1.30N/mm2 - 8.03 N/mm2, 120N/mm - 833N/mm and 142.072 J/mm3 - 656.570 J/mm3 respectively in longitudinal loading positions to 600N - 2100N, 2.221 N/mm2 - 9.047 N/mm2, 57.14N/mm2 - 800 N/mm2 and 486.666 N/mm2 - 857.046 N/mm2 respectively in lateral loading position at the various moisture contents. Generally, the compressive strength of the horse eye bean seeds is higher at lateral loading position than at the longitudinal loading position.
This research was carried out to simulate microalgae oil hydroprocessing plant using ASPEN HYSYS simulation package. The simulation is based on conditions and parameters (temperature, pressure and catalyst selectivity) obtained from consulted literatures. After the successful completion of the simulation, total recovery of products for green diesel and propane was achieved as 85.6% and 4.01% (mass percentages) respectively. The green diesel composition indicated 0.01, 0.0005, 0.0201, 0.0757, 0.0021, 0.0089, 0.0041, 0.1813, 0.6822, 0.0191, and 0.005 mass fractions of n-C15, n-C16, n-C17, n-C18, n-C21, i-C15, i-C16, i-C17, i-C18, i-C21 and H2O respectively. The quality specifications of the simulated Green diesel with Cetane number 86.7 fall within acceptable range and met the United State diesel standard ASTM D975. A complete disappearance of triglycerides in the product mixture at the hydrotreating temperature of 371 °C and pressure of 20 bar was observed. Economic analysis of the simulated project gives a total capital cost of ₦5.184billion, total production cost of ₦5.01 billion and cash flow as revenue of ₦6.02 billion after the fourth year. It shows that the project is highly profitable and efficient with a pay-back period of approximately 4years.
Many vehicles on the highway move at speeds below the design speed obviating overtaking maneuvers by vehicles that move at the design speeds. The paper is an attempt to formulate a model to determine the minimum overtaking sight distance to be maintained by the slope-ascending overtaking vehicle driver on an inclined double lane divided highway. The vehicle and road user characteristics as well as the vertical road geometry are combined to assess the overtaking distance by formulating a mathematical model that satisfies the laws of the mechanics of motion.
The behaviour of semiconductor devices at the microwave frequencies could be easily understood when the devices are represented by lumped networks. This paper has shown that the diode because of its smallness compared to the wavelength of the applied field could be used as a lumped element and the p-i-n diode serves as a good candidate for this purpose. The forward and reverse were seen to follow near normal diode characteristics bias impedences. The effect of insertion loss or minimum attenuation as well as impact of isolation on attenuation were verified. These effects were tested on P-I.N diode for single and multiple throw switches. The work showed that for two single switching circuits, there was minimum transmission coefficient of 0.94 at 3.2GHz and maximum of 0.11 at zero bias. For double switching grant, the minimum transmission coefficient was 0.92 with a maximum of 0.07. The isolation increase as the number of diodes increased, moving from 44db for double diode circuit to 53.9dB for three.
The Editor in Chief, Journal of Experimental Research Department of Anatomy, Enugu State University of Science and Technology, College Of Medicine (ESUCOM), GRA Enugu, Nigeria.
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Enugu State University of Science and Technology