LAUTECH Journal of Engineering and Technology

EFFECTIVENESS OF ELECTRO-COAGULATION TREATMENT METHOD ON THE PHYSIO-CHEMICAL PARAMETERS AND HEAVY METALS IN RUBBER LATEX WASTEWATER

E. O. Fakorede — 2020-08-21

Electrocoagulation has been employed as a treatment technique for treating various wastewaters. This study focuses on the performance of the electrocoagulation process for the treatment of rubber latex wastewater (RW) using Aluminum-Aluminum (AL-AL) and Aluminum-Carbon (AL-C) electrodes. Rubber latex wastewater (RW) was obtained locally from the plastic industry in Araromi-Obu, Ondo State of Nigeria with an initial concentration of 7.30, 28°C, 65.53mg/L and 785.23mg/L for pH, Temperature, BOD, and COD respectively and subjected to electrocoagulation using (AL-AL) and (AL-C) electrodes. Effects of electrocoagulation time and electrode types were studied and achieved under the following initial conditions of 30V, current density of 15mA, inter-distance electrodes of 1.5cm. The results revealed that this process could reduce the concentration of BOD, COD and Lead in RW. The highest removal efficiencies of 98.74% and 98.47% (COD); 82.02% and 79.12 (BOD); 90% and 83.33% (Lead), were obtained for AL-AL and AL-C electrodes respectively. From this study, it can be concluded that electrocoagulation is effective in the treatment of RW. It is recommended that Rubber producing industries could adopt this treatment method to treat their wastewater rather than disposal into the environment without treatment.

REVIEW OF SELECTED POZZOLANAS FOR CONCRETE PRODUCTION

S. O. Odeyemi — 2020-11-21

In pursuit of producing a sustainable and durable concrete composite, there is need to incorporate some supplementary cementitious materials to modify its conventional properties. Several works have been done on the utilization of agricultural and industrial wastes as pozzolans in concrete. However, there are some naturally occurring materials that also exhibit additional binding tendency that are yet to be explored. Cement being a conventional binder in concreting undergoes hydration reaction producing lime as one of its by-products. This causes expansion thereby predisposing the composite to disintegration and hence, untimely failure. Pozzolans have the tendency of forming additional binding property when in contact with this lime in the presence of water. Lot of research has been carried out on its properties and effects in concrete. However, there have been disparities in the optimum percentage replacement of various pozzolans in concrete. This article focuses on previous findings on the utilization of pozzolans in concrete and its prospects in the

IMPACT OF ELEMENT LENGTHS AND SPACINGS ON THE PERFORMANCE CHARACTERISTICS OF YAGI-UDA ANTENNA

A. A. Raji — 2020-11-21

This work examines the impact of element lengths and spacing on the performance behaviours of Yagi-Uda antenna. Four Yagi-Uda antenna types are used as candidates for numerical investigation including Yagi-Uda antenna of uniform lengths of directors with uniform spacings (YUDUS), Yagi-Uda array of uniform lengths of directors with non-uniform spacings (YUDNS), Yagi-Uda array of varying lengths of directors and uniform spacings between directors (YVDUS), and Yagi-Uda antenna varying length of directors with non-uniform director spacings (YVDNS). Upon utilizing method of moments procedure, far-zone radiation field, directivity, front-to-back ratio, and side lobe radiation emerge and are therefore utilized as performance metrics for analyzing the behaviour of those Yagi-Uda antenna types. It is observed that YVDNS exhibits better directive main lobe radiation and lower side lobe radiation than others. It is observed also that YVDNS has maximum front-to-back ratio which suggests better electromagnetic energy radiation than others. These characteristics properties of YVDNS design commend the antenna for a number of practical applications more than any other type of Yagi-Uda antenna.

OPTIMIZATION OF OPERATION PARAMETERS OF A DEVELOPED DOUGH MIXER

A. Fadeyibi — 2020-11-21

A mixer is essentially required for homogenizing flour and other ingredients in the bakery industry. In this research, a dough mixer was developed using a 10.5% chromium stainless-steel and its performance evaluated based on the machine parameters. The shaft speed (250−350 rpm), agitator geometry angle (45o, 60o and 90o) and number of blades (type A-5, type B-4 and type C-3) were considered as the machine parameters. The Effective mix proportion (EMP) was determined as the performance index. A Split-Plot Optimal Design was used to determine the desired variables for maximum EMP. Results show that the EMP decreases with an increase in the agitator geometry angle, irrespective of the speed of the mixing shaft. A critical behavior of the mixer was obtained at 300rpm, which indicates the homogeneous phase change stage in the mixing process. Again, the mixer performance was higher for the agitator with 5 blades and lower for the 3 blades agitator. The optimum EMP occurred for type C-3 blades, 60o geometry angle at 250 rpm with 98% desirability. These can be considered as the best configurations for a large-scale practice.

SELECTED ENGINEERING PROPERTIES OF PALM NUT (ELAEIS GUINEENSIS) REQUIRED IN THE DESIGN OF PALM KERNEL-SHELL SEPARATOR

F. B. Akande — 2020-11-21

Based on high dependence of many companies on palm kernel products for soap making vegetable oil and body cream, an efficient palm kernel-processing machine is therefore not only necessary but also important to regenerate the production of palm kernel oil in order to meet up with the ever increasing demand for the industries. Therefore, the knowledge of engineering properties becomes very important in the design of suitable and appropriate palm kernel-shell separator. The parameters investigated were linear dimensions, arithmetic mean and geometric mean diameters, surface area, sphericity, true and bulk densities, angle of repose, drag coefficient and terminal velocity of palm nut and kernel at 7.19 % and 9.5 % (d.b.) moisture content, respectively. The results revealed that average arithmetic mean diameter, geometric mean diameter, sphericity, surface area, angle of repose, drag coefficient and terminal velocity were 20.88/12.55 mm, 20.08/12.41 mm, 0.69/0.84 %, 104.67/485.31 mm2, 19.33/19.17 °, 1.93/1.22 and 5.72/3.21s m/s, respectively for nuts/kernel seeds. Some of the properties of the palm nut have been determined and found useful in the design and construction of palm kernel shell separator. These properties were needed as input to models or predicting the behaviour of agricultural produce in pre-harvest, harvest, and post-harvest conditions, to aid better understanding of processing and design of machines.

PROCESS OPTIMIZATION OF OIL EXPRESSION FROM WATERMELON (CITRULLUS LANATUS) SEEDS

R. A. Busari — 2020-11-21

Watermelon fruit contains large quantities of seeds and these seeds are under-utilized. It contains reasonable amount of oil (22%) which if expressed will serve as vegetable oil for human consumption or biodiesel for powering agricultural machines and boost the income of the farmers. The main objective of this research work is to study the interaction effect of operating parameters on the mechanical oil expression from the seed. The variables considered include applied pressure (85.00, 90.00, 95.00, 100.00 and 105.00 kN/mm2), roasting temperature (70.00, 80.00, 90.00, 100 and 110 °C) and moisture content (6.00, 8.00, 10.00, 12.00 and 14.00 %). A total sum of 20 batch experiments were carried out and the maximum oil yield was 13.49% (at corresponding moisture content of 6.00%, roasting temperature of 85.00oC and applied pressure of 105.00 kN/mm2 respectively) and minimum oil yield obtained was 9.41%.(at corresponding moisture content of 14.00%, roasting temperature 80 °C and applied pressure of 85.00 kN/mm2 respectively). While the optimum oil yield of 12.42% was obtained from the expression at corresponding moisture content of 6.00%, roasting temperature of 80.00ºC, and applied pressure of 105.00 kN/mm2. The result showed that the three independent variables had significant effect on oil yield and regression model equation was developed to predict the oil yield from watermelon seeds at known variables.

DEVELOPMENT OF A NEURAL NETWORK MODEL FOR IDENTIFYING BULK COWPEA SEEDS VARIETY USING ITS ELECTRICAL PROPERTIES

J. Audu — 2020-11-21

Artificial intelligence using machine leaning algorithms are modern trends in global industrialization. For agriculture to meet the global demand, the need to automate it processes are crucial. The objective of this study was to develop an artificial neural network model; that will be used to detect and identify variety of cowpea seeds in large storage facilities, using its electrical properties. Electrical properties of three variety of cowpea were generated; at five different moisture content, with five different current frequencies. A three-layer model was developed using multi-layer Perceptron method. It was trained and optimized using batch and scaled conjugate gradient methods respectively. Activation functions used were hyperbolic tangent and Softmax for the hidden and output layers; covariates in the input layer were standardized. The developed network model identifies 96, 97 and 93% varieties correctly during training, testing and validation respectively. Receiver Operating Characteristics (ROC) curve plotted for the model performance shows areas under the curve to be above 0.9 for all variety identified. This shows that the model performance was over 90% for predicting all varieties. The cumulative gain and lift charts were plotted to evaluate the model. Inductance was diagnosed to be the most important predictor to the model, while current frequency was the least. Pair t – test analysis at p<0.01, was done to further validate the model. This developed artificial neural network model can be used to program electrical sensors to identify cowpea seeds varieties during bulk storage, handling and processing. Such device can be used for quality control.

BIO-TRANSFORMER OIL PRODUCTION BY ENZYMATIC TRANSESTERIFICATION OF PAPAYA SEED OIL

O. A. Oyelaran — 2020-11-21

Bio-transformer oil from vegetable oil has received quite attention as a substitute to mineral based transformer oil with a view of minimize mineral based oils and reduce greenhouse gases pollution. The seeds of papaya are potential feedstock for bio-transformer production owing to their high lipid contents and available. In this study, papaya seed oils was extracted via soxhlet apparatus using n-hexane and the oil yields were in between 34–35% which is commercially viable. The oil extracted was transesterified using immobilized Candida rugosa lipase as a catalyst at room temperature with various molar ratios of methanol to oil. The highest bio-transformer oil yield for papaya seed oil was found to be 96% at methanol-to-oil ratios of 6:1. The results obtained from the characterization of RPSO bio-transformer oil was analytically compared with that of the transformer mineral oil and ASTM standard requirement. Similarities and differences have been discussed. Owing to comparable results in the RPSO bio-transformer oil, mineral transformer oil studied and the ASTM standard requirement and its increasing breakdown voltage with increasing temperature application. The study revealed that papaya seed oils have the potential of being used as alternative feedstock for bio-transformer production.

MOISTURE ABSORPTION CHARACTERISTICS AND ADAPTIVE NEURO FUZZY MODELLING OF AMPELOCISSUS CAVICAULIS FIBER REINFORCED EPOXY COMPOSITE

A. J. Adeyi — 2020-11-21

Natural fibre reinforced composite is fast becoming an important class of engineering materials due to its low cost, light weight and good mechanical properties; therefore increased natural fibre composite development is desirable. In this study, the effect of water soaking time and Ampelocissus cavicaulis natural fiber (ACNF) size factors on the water absorption characteristics of ACNF reinforced epoxy composite was investigated. The optimum membership function in Adaptive Neuro Fuzzy Inference System (ANFIS) structure that modelled and predicted the observed water absorption characteristics of the developed composite was investigated by giving consideration to minimum training error. ANFIS was also utilized to evaluate the sensitivity of ACNF reinforced epoxy composite’s water absorption characteristics to water soaking time and ACNF size factors. Results showed that developed composites’ water absorption increased as water soaking time and ACNF size increased. While optimising the ANFIS structure, the training error associated with ANFIS gauss, tri, gbell, gauss2, pi and gsig memmbership functions were 0.5171, 0.08997, 0.6706, 0.08803, 1.3770 and 0.6167, respectively. The optimum ANFIS model structured (trimf) had a coefficient of determination (R2) value of 0.99947. The water absorption characteristics of ACNF reinforced epoxy composite was most dependent or sensitive to water soaking time with a root mean squared error (RMSE) of 1.577 followed by ACNF size with RMSE of 1.753. It is concluded that ACNF reinforced epoxy composite are best applied in non-moist or dry environments.