Arid Zone Journal of Engineering, Technology and Environment (AZOJETE)
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Development of an NCAM Tuber-Shaped Vegetable Slicing Machine
Get PDFGenerally, most agricultural products are not stable immediately when freshly harvested, while their preservative nature varies accordingly especially, vegetables and fruit crops. The need to process and preserve them in a stable form is very important. In processing of some tuber -shaped vegetable crops such as carrot, plantain, cucumber, eggplant, etc., slicing/chipping is usually done traditionally with the aid of knives and other manual methods which are time consuming, thereby exposing processors to dangers of injury, increases drudgery and overall reduces productivity. In respect of these, an NCAM tuber - shaped vegetable slicer was designed, fabricated and evaluated. The performance parameters used for the evaluation are slicing efficiency, slice thickness and percentage damage. IBM SPSS 2.0 was used to analyse the result obtained from the performance evaluation of the tuber – shaped slicer. It was observed that blade thickness had a significant effect on percentage damage and slice thickness, and no effect on slicing efficiency at p≤0.05. 94.74% and 90.99% efficiency was observed at 1.5 mm and 1 mm blade thickness for plantain and cucumber respectively. Furthermore, the highest mean value for percentage damage for plantain was 44.08% at 1.0mm blade thickness, while the highest mean value of percentage damage for cucumber was 24.88% at blade thickness of 1.0mm. This shows that the tuber – shaped vegetable slicing machine performed efficiently. Therefore, tuber-shaped slicing machine is recommended for use by processor of tuber – shaped crops into other stable form.
 
Improved Gearless Transmission System
Get PDFGearless transmission is an elbow mechanism that transmits power with little losses. The system is mainly used to reduce the usage of complex gears likewise the wearing conditions of the gears that requires high cost of repairs and or maintenance. Therefore, exploration into this study lead to rejuvenate ideas through which power was transmitted using different mechanism by replacing a bevel gear with an elbow mechanism for transmitting the power between the two shafts at 90°. The mechanism hubs were fixed at both ends of the shafts through which power was transferred. The sizes of the pins and links were measured, likewise the holes were drilled precisely. In this study, three elbows were connected radially at an angle of 120° to the center of the axis. The transmission was made cost-effective and efficient with the average efficiency of 94.8% and a complete freedom of interchangeability whereby the total cost of production was #76,000. Of this arrangement, the mechanism has effective and minimum amount of power (10.18Nm) at the handle needed for a complete revolution. It’s a simple working principle, smooth with an effective and lesser power needed to propel it.
 
Department of Agricultural and Environmental Resource Engineering, University of Maiduguri, Borno State, Nigeria
No full textAustempering heat treatment is a proven way of obtaining the desired microstructure for improved mechanical properties. It is an isothermal heat treatment process in which an attractive combination of mechanical properties of austempered ductile iron (ADI) may be produced. In this paper, a statistical model for the determination of some mechanical properties was developed. The ductile cast iron was annealed after which it was austennitized at 850 and 950 °C. After the austenitizing process, it was then austempered in hot jatropha seed oil. The developed prediction model was then utilized to assess the tensile strength and hardness of the ADI. The result of the austempering process showed appreciable improvement in tensile and hardness values measured. Optimum values of tensile and hardness were 962 kN/mm2 and 405 BHN respectively. Values of 961.4N/mm2 and 340.1BHN were obtained using the developed model. It can therefore be concluded that, the closeness in the values obtained from the experimental measurement and the prediction model is an indication of the effectiveness of the developed model.
 
Effect of Drying Conditions on the Drying Kinetics and Colour Changes of Plantain (Musa X Paradisiaca) Slices using Combined Heated Air and Infrared Dryers
Get PDFMost agricultural crops with high moisture content are difficult to preserve. The most common method of preservation is drying. Thus, drying operation where a combination of two or more modes is used, could speed-up drying process. However, the scalability of combined heated air and infrared drying (CHAID) for rural consumers have not been investigated. This study was conducted to examine the effect of drying conditions (temperature and infrared intensity) on the drying kinetics and total colour changes (∆E) of plantain slices using a CHAID dryer. Matured unripe plantain samples were sourced from a market, peeled, washed in running water and then sliced into 4 × 20 × 20 mm dimension. Initial moisture content (MCi) determined using oven drying method. 2.0 g of the sliced sample were weighed and dried in a combined heated air and infrared dryer (IR) operated at 800 W/m2 alone till the mass (bone dry mass) did not vary after repeated weighing. Also, samples ∆E was monitored using colorimeter within the drying period. The same procedure was repeated using heated air-drying mode (HAD) operated at 65 ± 2 °C; IR-800 W/m2 plus HAD at 65 ± 2 °C, and IR-1000 W/m2 plus HAD at 65 ± 2 °C. The moisture content (MC) and drying rate were computed from duplicate data using Microsoft Excel programme. The variation of % MC with drying time, drying rate against MC and ∆E versus drying time were made and ∆E compared using Tukey Honest Significant Difference. Results showed that the samples’ MCi by oven dried method was 55.84%wb whereas those dried using IR-800 W/m2 alone, HAD (65 ± 2 °C) alone, IR-800 W/m2 plus HAD (65 ± 2 °C) and IR-1000 W/m2 plus HAD (65 ± 2 °C) modes were 57.43, 52.13, 57.41 and 57.03% wb, respectively, and their corresponding critical or equilibrium moisture content were 5.62, 5.03, 12.45 and 5.95%wb, respectively. Similarly, a shortest drying time (30 mins) and minimal total colour changes (ΔE = 12.42) were found when IR (1000 W/m2) plus HAD (65 ± 2 °C) was used. It also observed that, plantain slices dried using HAD (65 ± 2 °C) mode showed statistically significant mean difference in ΔE when compared with other three drying modes within 10 to 30 minutes drying time. Since, IR (1000 W/m2) plus HAD (65 ± 2 °C) mode gave shortest drying time and minimal ΔE, it is recommended for use in drying plantain slices by restaurant, hotels operators and food processors.
 
Arc Flash Study of IEEE 8 Bus Test System using Digital Simulation and Electrical Network Analysis Platform
Get PDFNowadays, electricity plays an important role in our life and in our industries. However, when an arc fault occurs, it creates an incident that can cause a serious damage to the equipment and can cause serious injury to the workers. Arc fault is generated when electric current passes through air from one uncovered live conductor to another or to ground in electrical system. Analyzing the level of arc flash and providing a good protection to the workers is paramount. In this work DigSILENT software was used to study the Arc Flash of Institute of Electrical and Electronics Engineers (IEEE) 8 Bus Test System. Firstly, a model of system was created in the DigSILENT environment and then arc flash study of all the buses in the system was carried out. Based on the simulation results obtained, Personnel protective equipment and labels were generated to inform the workers about the level of danger they are exposed to in the course of doing their work. The risk category for buses numbers 3 and 7 are cat 2 and 3 respectively while for buses 1and 5 and for buses 2,4,6 and 8 are cat 4 and 5 respectively. The results showed that there is a need for the personnel to equip themselves with the appropriate Personnel Protective Equipment (PPE) as suggested before access. Because, arc flash faults have significant effect on personnel and equipment. It’s really important for stability, energy continuity, human life and economy.
 
Prediction of Infant Size at Birth Using Principal Components based Artificial Neural Network
Get PDFBirth size plays a major role in child’s mental development, future physical growth, and survival. The average length of full-term babies at birth is 20 in. (51 cm), although the normal range is 46 cm (18 in.) to 56 cm (22 in.). In the first month, babies typically grow 4 cm (1.5 in.) to 5 cm (2 in.). Principal Component Analysis (PCA) is a dimension-reduction tool that can be used to reduce a large set of variables to a small set that still contains most of the information in the large set. In neural networks multicollinearity may increase difficulties in data processing; too much feature inputs will also cause the time-consuming training process, prevent the constringency of the training work, and may eventually affect the network performance. This research investigates the effect of some parents’ socioeconomic status on the sizes of infants at birth in Zamfara State. Several factors have been identified to have effect on the sizes of infant at birth which is part of major public health challenges in developing countries like Nigeria. Previous studies considered only some maternal factors responsible for the infant sizes at birth. This current study explored the parents’ socioeconomic Status and environmental factors that contributes to the status of the infant sizes at birth using factor and neural network analysis. The analysis was carried out using data collected from Federal Medical Centre, Gusau and Ahmad Sani Yariman Bakura Specialist Hospital Gusau, Zamfara State to explore the association between the afore mentioned factors. Multicollinearity results indicated that there is significant correlations among independent variables, factor analysis through principal extraction methods reduced the original 14 correlated variables in to five uncorrelated factors. However, artificial neural network performs better in the presence of multicollinearity as it produces lower mean square error (MSE). It also had a better classification accuracy of 83.5% as compared to 65.9% for Gender of the baby.
 
Evaluation of the Mechanical Properties of Surface Modified Ukam Fibre Reinforced Polyester Composites
Get PDFThis work evaluated the properties of ukam fibre reinforced polyester composites. The ukam fibres were subjected to different surface treatments including alkaline, saline, permanganate and acetylation. Composites were produced at 5%, 10%, 15%, 20% and 25% fiber loadings and its mechanical properties determined. The results found that the most suitable mixture for excellent improvement in mechanical properties was obtained with the 25% fibre and 75% resin. Additionally, the results showed improvements in mechanical properties with surface treatments at all fibre loadings. Furthermore, it was observed that Fibre Surface treatment leads to compatibility which resulting in good load transfer between the modified fibre and matrix. Whereas acetylation treated composites exhibited the highest values of hardness at all levels of fibre loading, alkaline treated samples exhibited the highest tensile and compressive strengths at all fibre loadings. It is noteworthy that saline treated composites exhibited highest impact and flexural modulus of rupture. Interestingly, there was no significant improvement noticed with potassium permanganate treated reinforced fibre composites. Therefore, the results clearly showed that alkaline, saline, and acetylation fibre surface treatment methods could be used to produce ukam fibre composites with good mechanical properties for potential engineering applications.
 
Evaluation of Evaporative Cooling Structure (ECS) and Artificially Aerated Onion Structure (AAOS) for Storage of Fresh Red Onion.
Get PDFStorage of onion usually by cooling has been problematic due to poor electricity supply. Thus, this study assessed the effectiveness of artificially aerated onion structure (AAOS) and evaporative cooling structure (ECS) for the storage of fresh red onion. A total of 4650kg of red onion was stored for 7 months (March to October) and was monitored monthly to observe physiological and biochemical changes using AAOC and other standard methods. Data collected were subjected to descriptive statistics and t-test at significant difference of P<0.05 using SPSS. Increase in the percentage weight loss of the stored onion was observed as relative humidity increased especially when the relative humidity surpassed 50%. ECS had 27.03% weight loss recorded in May (2nd month of storage) while AAOS had 11.1% weight loss in July (Fourth month of storage). At the end of the experiment the average weight loss was 65.76%, 72.00%, and 76.12% for AAOS, Conventional method and ECS respectively. There was an increasing trend in the proteins, carbohydrates and oil contents of onion in AAOS and were significantly (p < 0.05) higher than the increase in conventional storage method and ECS. Declining trend was observed in ascorbic acids (AA) contents in the stored onions in all treatments leaving more retention (10.4% AA and 5.48% AA), in AAOS and conventional storage method respectively more than in ECS. Total polyphenolic contents increased from an initial 5.10±0.02 to 12.08±0.00, 9.95±1.03 and 8.97±1.03 GAE (mg/g) fresh weight in AAOS, conventional storage method and ECS respectively.
 
Estimating the Collapse Point of a Transmission Line in a Developing Power Systems
Get PDFThe trouble with a developing national grid is compounded by the fact that the power system supplies power to a vast number of loads which is fed by a number of generating units sometimes far from the load centers. Variations of loads bring about power losses and corresponding increase in the reactive power requirements of the transmission systems. Thus, the paper is aimed at establishing the point of collapse of transmission lines to enable a control system operator to take proactive measures in the event of small/large system disturbances. Voltage collapse proximity indicator is exploited to show that the variations in load close to the maximum load require extremely large amounts of reactive power at the sending end in order to support the increase in load. In the work, it was identified that Katemkpe-Shiroro transmission line is the most critical transmission line contributing immensely for voltage collapse scenarios in Nigeria national grid. Consequently, it ranked first because it has the highest voltage collapse proximity index. Computation involving voltage collapse proximity indicator obtained the collapse point or the knee point as 2.8684. This serves as a criterion that will enable control system expert to take proactive measure before the impending voltage collapse
Design, Analysis and Construction of an Impressed Current Electric Device for Cathodic Protection
Get PDFThis paper aimed at designing, analyzing and fabricating an impressed current electric device. Cathodic protection is a means to prevent corrosion by applying a flow of electrical current from an external source (anode) through the environment and to the metallic structure that is being protected. The protective current changes the environment around the metal thus halting the corrosion reaction. Cathodic protection is used to prevent corrosion in a wide range of applications where the structure being protected is surrounded by an environment that allows current flow. The impressed current cathodic protection systems have the benefit of using an external power supply to drive current. The study used sea water as electrolyte with locally constructed transformer rectifier and to select a proper material for the construction so as to illustrate the effect and how the impressed current system functions. The general performance evaluation was found that the device has a net driving potential of 10.5V and a life expectancy of 128 years of the anode. In conclusion, the construction was successful and easy to operate which can be used to protect metal structure against corrosion