Arid Zone Journal of Engineering, Technology and Environment (AZOJETE)
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Moisture and Temperature Influence on Thermal Properties of Winged Bean (Psophocarpus tetragonolobus) Seed Accessions
Get PDFThe thermal properties of three winged bean seed accessions (Entry 4 Tropical Psophocarpus tetragonolobus (TPT) 6, Entry II Tropical Psophocarpus tetragonolobus (TPT) 30, and Entry 12 Tropical Psophocarpus tetragonolobus (TPT) 32) at 5, 10, 15, 20, and 25% moisture contents and 30, 40, and 50 ᵒC temperatures were determined with the KD2 Pro Thermal Analyzer. The results showed that the thermal properties of the seed accessions were moisture-temperature dependent. Entry II TPT 30 had the highest specific heat capacity (1.37-2.59 kJ.kg-1K-1), while Entry 4 TPT 6 had the highest thermal conductivity (0.17-0.60 W.m-1K-1) and thermal diffusivity (0.19-0.77 x 10-7 m2.s-1) as the temperature and moisture increased. A second-order polynomial model described the relationship between the moisture, temperature, and the three thermal properties studied. Respective high correlation coefficients (R2 ≥ 0.9126, 0.9872, and 0.9801 for Entry 4 TPT 6, Entry II TPT 30, and Entry 12 TPT 32 accessions, respectively) indicated their ability to simulate these parameters within the moisture-temperature domain studied. The winged bean seeds' thermal properties will be used to guide design decisions for the creation of agricultural machinery, thermal processes, and equipment required for storage, drying, heating, and cooling.
 
Evaluation of pyrolyzed oil palm frond in the adsorption of residual phenolic compounds in facultatively treated palm oil mill effluent
Get PDFAerobic digestion is the final stage of biological treatment systems employed for treating Palm Oil Mill Effluent (POME). The presence of phenolic compounds in POME inhibits the performance of aerobic microbes. To mitigate the inhibitory effect, removing phenolic compounds at the early stage of aerobic treatment could be a workable solution. In this study, the performance of biochar from oil palm frond (OPF-BC) prepared using steam pyrolysis was investigated for the efficient removal of phenolic compounds. Adsorption kinetics and equilibrium tests were performed to assess the time required to reach adsorption equilibrium and uptake capacity for phenol, catechol and gallic acid spiked in water and facultatively treated POME. Adsorption of the phenols onto OPF-BC attained equilibrium within 2 h irrespective of the water matrix. In the water maximum adsorption capacities of 38.7, 28.2 and 26.2 mg/g were obtained for phenol, catechol, and gallic acid, respectively. The presence of background organic matter in facultatively treated POME reduced the adsorption capacities by 3-folds. The simplified equivalent background model estimated dosage to achieve 80% removal ranged between 14.4 and 18.8 g/L. The OPF-BC demonstrated efficient phenolic compounds removal performance, making it a promising and economical adsorbent for the hybrid adsorption-aerobic treatment system.
 
Influence of Antimony Micro-Alloy Addition on the Mechanical Properties of Carbidic Austempered Ductile Iron (CADI)
Get PDFIn this research work, the influence of antimony micro-alloy addition on the hardness property, impact energy and wear resistance of carbidic austempered ductile iron (CADI) was investigated. Rod-shaped samples were produced using a sand casting technique to investigate the influence of antimony micro-quantities on the microstructural modification of the high manganese content (CADI). Selected mechanical properties of the product (CADI) have been tested. Rod-shaped samples were produced using a sand casting technique to investigate the influence of antimony micro-quantities on the microstructural modification of the high manganese content (CADI). Selected mechanical properties of the product (CADI) have been tested. Rod-like shape samples were produced by sand casting technique used for evaluating the influence of micro - quantities of antimony on the microstructural modification of high manganese content carbidic austempered ductile iron (CADI) with respect to the selected me 7chanical properties. Six compositions of carbidic ductile iron (CDI) with varying antimony content ranging from 0.096 % to 0.480 wt. % were produced, having equivalent carbon of hyper-eutectic composition (4.43). These samples were heated to austenitic temperature of 910ºC and subjected to austempering temperature, 300ºC for period of 1-3 hours. Microstructural examination of the samples was carried out to study the matrix and reinforcing phases present. The abrasion wear resistance was evaluated in accordance with the ASTM G 65 standard. The results show that; the obtained wear resistance values ranging from 2.35E8 to 3.29 E9 with respect to unmodified CADI (taken as reference material) The results show that the wear resistance values ranging from 2.35E8 and 3.29 E9 with respect to CADI sample without antimony addition taken as reference material, Rockwell hardness values obtained ranging from 28.6 – 55 HRc and impact toughness values ranges from 46.5 – 53 J for the developed CADI. Micrographs obtain revealed that chunky graphite, blocky carbides and pearlite phases were seen in the as-cast sample without antimony addition while the samples with varying addition of antimony element showed spiky graphite, granular carbide and more pearlite phases. However, after subjecting the samples to austempering processes, the pearlite phase transformed to ausferritic structure, while the carbide and graphite structure remained unaltered. The produced CADI is found to be useful for agricultural implements production.
 
A Resource Performance Model for Efficient Distribution of Resources to Operating System Services in Factored Operating System
Get PDFCentral processing will be composed of thousands of heterogeneous cores in the near future. The existing systems are difficult to scale, adapt or tackle the heterogeneous nature of the future multicore technology. This study developed a resource performance model for efficient distribution of resources to Operating System (OS) services. A Multi-Agent based method was used to design the architecture of the model while the Unified Modeling Language and flowchart were used in the detailed design of the proposed model. The model was simulated using Java 2 Enterprise Edition. In simulating the model, four (4) variables were used to determine the processor core capacity. The result of the simulation shows an efficient distribution of 5000 cores to four (4) OS services (servers) with each having 1250 fleet of servers. The percentage differences in the four of servers from the minimum are 0.11%, 0.09% and 0.04% respectively. The result shows that the distribution of processor cores to OS services is efficient since the differences in total performance function of the fleets of servers were very little. Therefore, to maximize the profit that comes with multicore systems, this efficient model is needed for processor cores distribution to OS service in a Factored Operating System.
 
Effect of Bio-Cementation on the Strength Characteristics of Compacted Lateritic Soil Under Sterilized and Unsterilized Conditions
No full textNaturally, not all soils readily meet specifications for engineering use. Therefore, improvement of soil engineering properties is one of the main concerns of a civil engineer. This paper evaluates the strength characteristics of a deficient lateritic soil classified as an A-4(3) using the American Association of State Highway and Transportation Officials (AASHTO) classification system and CL using the Unified Soil Classification system (USCS) after improvement, using microbial induced calcite precipitation (MICP) technique. The soil sample was obtained from a site in Abagana, in Anambra State. It was treated with varying suspension densities up to 2.40 x 109 cells/ml of Sporosarcina pasteurii (S. pasteurii) a non-pathogenic microorganism cultured from the soil, under sterilized and unsterilized condition. The treated soil was compacted using the British Standard Light (Standard Proctor) compactive effort at the moulding water content range of -2 to +4% optimum moisture content (OMC). The compacted soil specimens were then permeated a cementitious reagent containing 20 g of Urea, 10 g of NH4Cl, 3 g of Nutrient broth, 2.8 g of CaCl2 and 2.12 g of NaHCO3 per litre of de-ionized water to aid the microbial induced calcite precipitation (MICP) process in three circles with 2/3rd pore volume. The Atterberg limits results showed a better improvement in the sterilized than the unsterilized specimens. Similarly, the unconfined compressive strength generally recorded higher results in the unsterilized specimens. Highest unconfined compressive strength (UCS) results were recorded at S. pasteurii suspension densities of 1.20 x 109 /ml and 1.80 x 109 /ml for the unsterilized and sterilized specimens respectively. Microstructural analysis using X-ray Diffraction performed on precipitates derived through the interaction of S. pasteurii and the cementitious reagent confirmed calcite as the dominant composition of the precipitate, analysis using the scanning electron microscopy (SEM) on the MICP treated soil depicts presence of calcite precipitate and bio-cementation on the surface morphology of the treated soil grains. It was concluded that there are other species of microorganisms that augmented the MICP processes in the unsterilized specimens resulting to higher UCS values in the study. 1.20 x 109 /ml S. pasteurii suspension density was recommended as the optimal mix for the treatment of the unsterilized soil
Implementation of Numerical Integration Using Field Programmable Gate Arrays and Microcontrollers: A Review
Get PDFMajority of numerical integration algorithms are written in software and require a long time to initialize and generate results. There is a gradual shift from software-based designs to (Field Programmable Gate Arrays (FPGA)-based designs because they are versatile devices that are increasingly being used as real-time hardware targets in industries. FPGAs are utilized in real-time measurement and control, signal processing, and digital communication, among other applications, because they are inexpensive real-time reconfigurable devices. Because of the high increase in the volume of data used in designs and the large data dependencies in complex computations, researchers are motivated to highlight the need for a shift from the software based implementation of numerical integration to hardware-based FPGAs implementations that are much quicker, more efficient, and more reliable. In this paper, different numerical integration implementations are studied, their strategies discussed, findings assessed and recommendations drawn to enable the suggestion of a better way of improving them. A tabular summary of the review is provided to enhance the understanding of the findings of the review and recommendations for each of the implementations. Based on the review, it can be deduced that FPGAs implementations are faster than software based implementations in C++ and Matlab. It is also evident from the review that architectural designs like pipelining and parallelism when employed on FPGAs greatly improve the throughput of designs and models which significantly reduce data dependencies. It is recommended that FPGA implementation should be employed in the development of numerical integration algorithms due to their low cost, power consumption, small size, and high speed.
 
Conversion of Biomass to Adsorbent: A Review
Get PDFTons of biomass are produced every year including organic agricultural and forestry by-products but they are of limited value. Mostly, in the developing countries, the biomasses are considered as waste and are being burnt or thrown to liter the environment as part of teaming solid waste. Presently, there are no sustainable long-term management strategies to use biomass. The utilization of biomass to produce activated carbon is a good approach that is industrially useful and environmentally benign materials. The adsorption technique is using adsorbents in the removal of heavy metals from water therefore, biomass can be converted to the adsorbent and utilized as a waste-to-wealth commodity in water purification. In this review, the suitable process for conversion of biomass to cheap and simple means of obtaining activation carbon as adsorbent is presented. The potential uses of biomass and the conversion stages including carbonization, pyrolysis, gasification, and activation were discussed. This work depicts that the issue of solid waste utilization to solve existing issues with locally available and cheap materials is beneficial to man and the environment
Evaluation of Best- Fit Probability Distribution Models for Prediction of Rainfall in Southern Nigeria
Get PDFSuitable and adequate hydrological design data especially for flood design, are not readily available. When data is available, it is often outdated and irrelevant to current events especially in this era of global warming and climate change. This study presents rainfall frequency analysis for some cities in Southern Nigeria using the annual maximum series of daily rainfall data for the stations. The objective of the study was to select the probability distribution model from among six commonly used probability distribution models namely: Generalized Extreme value distribution (GEV), Extreme value type I distribution (EVI), Generalized Pareto distribution (GPA), Pearson Type III (PIII), log Normal (LN) and Log Pearson Type III (LP111) distributions. These distributions were applied to the annual maximum series of daily rainfall at each station using the parameters of the distributions estimated by the method of moments. The best fit probability distribution model at each location was selected based on the results of seven goodness of fit tests values with a scoring and ranking scheme. Our results indicate that the best-fit distribution models at the study locations are PIII for Ibadan and Benin City; GEV for Onitsha, Enugu, Owerri, Calabar, and Port Harcourt; EVI and LN for Uyo; EVI for Akure and LP111 for Ikeja. This implies that GEV performed better by occupying 50% of the studied area, followed by EVI and PIII which performed by occupying 20% each. These best fit probability distribution models are recommended for use for necessary design at each location for flood hazard mitigation.
 
An Independent Framework for Off-Grid Hybrid Renewable Energy Design Using Optimal Foraging Algorithm (OFA).
Get PDFThe rapidly increase in electrical energy demand from residential, commercial and industrial sectors is one of the major challenge in power system, especially in the current period of high oil prices, steadily reducing energy sources and increased concerns about environmental pollution. Renewable energy is considered as one of the solution to this increase in power demand. The conventional method of power system cannot meet the power demand for many reasons such as environmental effects, location of the consumer, price of fuel and others. This paper presents the design of an off-grid Hybrid Renewable Energy System (HRES) for electrification of a typical remote area. The designed hybrid system consists of three different configurations of PV/Battery, Wind/Battery and PV/Wind/Battery systems. The system components are modelled and the objective function is designed as a function of total annualized cost of the system subject to some constraints binding the decision variables. The total annual cost is formulated as a function of annual capital cost and annual maintenance cost of the system subject to some operational constraints. In order to determine the optimal number of the decision variables that would satisfy the load demand in the most cost effect manner, Optimal Foraging Optimization (OFA) algorithm was used. Finally, a simulation experiment shows that the total annual cost obtained by each algorithm for the PV/Battery system is 9,446.77 or N3,920,409.55 and 17,508.20 or N7,265,903, 16,535.93 or N6,862,410.95 respectively. Similarly, the PV/Wind/Battery configuration showed that the OFA, GA and PSO obtained an annualized cost of 18,167.09 or N7,539,342.35 and $16,535.93 or N6,862,410,95 respectively. From the results obtained by OFA are compared with that of Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) algorithm. Results showed that all the algorithm can efficiently size the hybrid system with OFA obtaining the most economical design. Therefore, for economically and efficiently electrification of a remote area in Abuja using an off-grid hybrid renewable energy system, GA optimization algorithm is recommended for wind/Battery system and OFA optimization algorithm is recommended for PV/Wind/Battery system.
 
Production of Biocomposite from Parinari Polyandra Fruit Shell Using Waste Low Density Polyethylene as Matrix
Get PDFEnormous wastes that are continuously being generated from low-density polyethylene (LDPE) film sachet water have remained an environmental challenge in Nigeria. These might require urgent action due to the non-biodegradability of LDPE. Biocomposite samples were produced using waste LDPE sachets and Parinari polyandra shells, where filler sizes (0.420 mm, 0.841mm) and filler loading (10%, 20%) were varied. In this study, a melt mixer was designed and fabricated for the production of bio composite samples. Biocomposite samples were characterized using tensile tests, compression test, flexural and impact strength test, water absorption test, biodegradability, fourier transform infrared spectroscopy and scanning electron microscopy tests. Viscosity of the bio composite mix was a major constrain in the design of the melt mixer. The results revealed that the optimum value of tensile strength was obtained with particle size 0.42mm at a 10% filler to matrix loading which produced a Young’s modulus of 320.321 N/mm2. Higher particle size and filler loading elicited a higher value for compressive strength based on a force at peak value of 27552.500 N. Flexural, impact and tensile strength decreased with increasing filler loading and particle size, while increased immersion time gave increased percentage of water absorbed