EXPERIMENTAL PREDICTION AND OPTIMIZATION OF MATERIAL REMOVAL RATE DURING HARD TURNING OF AUSTENITIC 304L STAINLESS STEEL

This work involves a predictive model for material removal rate (MRR). It investigates the influence of machining process parameters such as cutting speed, feed rate and depth of cut on the material removal rate (output parameter) during hard turning of AISI 304L austenitic stainless steel (0.03 wt. % C (max)). A total of 27 experiments were conducted using a MORISEIKI SL-253B CNC machine with cemented carbide cutting tool under three different spindle speeds (1000, 1200, 1400rev/min), feed rates (0.05, 0.10, 0.15mm/rev) and depths of cut (0.4, 0.8, 1.2mm). The machining parameter settings were determined using the Taguchi experimental design method. The Taguchi method and relationship between MRR and input parameters were arrived at through MINITAB16 software package. The optimum machining parameters combination was obtained by using larger-the-better analysis of signal-to-noise (S/N) ratio. The optimal cutting condition is at spindle speed level 2 (1200 rpm); feed rate at level 3 (0.15mm/rev) and Depth of cut at level 3 (1.2 mm) which gave an optimum MRR of 77.80243mm3/min. The S/N ratio response table, main effect plots and the relationship between cutting parameters and the MRR was obtained. A mathematical model was developed using multiple regression analysis to predict MRR during hard turning of AISI 304L austenitic stainless steel. The level of importance and performance characteristics of the machining parameters on MRR was determined by using analysis of variance (ANOVA). From the results, the feed rate had the most significant effects on the MRR followed by depth of cut.The spindle speed has the least effect on MRR. It was also revealed that the predicted results found a good correlation with the experimental results as the regression line fits well for both results data at 95% confidence interval.Keywords: Machining; material removal; optimizatio

EVALUATION OF VIABLE OPERATING STRATEGIES FOR PUBLIC TRANSPORT BETWEEN FUNAAB CAMPUS AND CAMP TERMINUS IN ABEOKUTA

Transportation is a live wire for national development regardless of a nation industrial capacity, population or technological development. It gives expressions to policy initiative in areas like health, education, employment, etc., and in the absence of it, these facilities would be inaccessible. Viable operating strategies for public transport between Federal University of Agriculture, Abeokuta (FUNAAB), Ogun State Nigeria Campus and Camp Terminus in Abeokuta were evolved. Traffic study was conducted for seven (7) days to determine traffic volume and peak periods (morning and evening) along the route. Questionnaires were administered to the road users to obtain factors (availability of vehicles, travel time from Camp Terminus to FUNAAB, road condition, operational cost, comfortability of the vehicle) needed to generate operating strategies. These factors were subjected to statistical analysis. The traffic volume revealed that Private cab had the highest traffic flow for a.m. peak period (8: 00 – 9: 00 am) from Mondays to Thursdays while Public cab had the highest on Fridays to Sundays, and at the pm peak period (4:00 – 5:00 pm), Public cabs had the highest traffic volume on Wednesdays, Saturdays and Sundays while the Private cabs had the highest on the rest days of the week. The analysis of the sampled population showed that public cab had the least total time travel (36.1 minutes) followed by mini- bus (37.8 minutes) while the school bus had the highest (43.7 minutes) and this justified the reason why 40% of the population choose to travel by public cab, 33% by mini– bus  and 27% by the school bus. However, for the viability of the operating strategies, more public cab and min-buses should be provided to ply the road because of their lesser travel time, also provision of more school buses because of the large number of passengers they carry per trip should be provided.     &nbsp

Metropolitan Infrastructure and Property Values: An African Experience

This paper evaluated impact of infrastructure in residential property on its property values in Ibadan, Nigeria. A total number of 450 questionnaires were administered out of which 423 questionnaires were retrieved. Both descriptive and inferential statistics were used to analyze the data collected for the study). The study revealed that burglary proof was seen as the strongest index of satisfaction in the study area, this was followed by security guard. Kitchen and fenced round ranked third and fourth respectively, while bathroom/toilet and access road ranked fifth and sixth respectively. Water supply ranked seventh, while drainage channel ranked lowest in the study area. The paper concluded that property developers that want to invest in residential buildings development should endeavor to provide infrastructure that will attractive rental values on their residential property in Ibadan in particular and towns and cities in developing nations

Seepage Investigation on an Existing Dam using Integrated Geophysical Methods

Integrated geophysical methods involving VLF-electromagnetic, magnetic intensity and electrical resistivity (ER), were employed to investigate the probable internal seepage at University of Ilorin Dam, Kwara State, Southwestern Nigeria.  Five (5) profiles were established in the south-north and west-east orientations, along the dam and reservoir axis. VLF-em conductivity response from -65 % to 50 % with estimated average anomalies of -7.5 % and; magnetic susceptibility distribution range between 2.27 nT and 756.24 nT, with average response of 163.6 nT suggests resistive basement rock contrasts in the area. Twenty seven (27) vertical electrical sounding (VES) points using the schlumberger array configuration were distributed along the profile lines. The lithologic units delineated with geo-electric sections established; 22 % wet/gravelly topsoil and 78% hard lateric pan – granitic outcrop having resistivity variation between 28.8 Ωm and 2612.8 Ωm with average response of 870 Ωm and thickness range of 0.8 m to 2 m; straddled with 22 % clayey - sand and 78 % sandy – clay, having resistivity distribution between 63.2 Ωm and 316 Ωm with average response of 148 Ωm and thickness range of 3.4 m to 8 m and; fresh bedrock. The area is underlain by fairly thin superficial soil (overburden) materials with an average thickness of 6.5 m which shows that the bedrock is close to the surface and serves as support to the dam. The clay materials which could serve as conduit, exist within the shallow overburden and has been excavated during construction. It is therefore concluded that the dam retains its strength and the observed reduction in reservoir water level could be a result of other environmental factors. Keywords: Unilorin Dam, internal seepage, anomalies, conductivity, weathered zones, geo-electric section

XYLAZINE-KETAMINE ANAESTHESIA; COMPARATIVE STUDIES IN MALE AND FEMALE CANE RATS (THRYONOMYS SWINDERIANUS)

Objective: Domestication of the Cane rats is on-going globally and might replace the conventional rodents used in biomedical research in future. However, the paucity of information on adequate anaesthesia vis-a-vis xylazine-ketamine drug combination in the male and female Cane rats warranted this study.Methods: Six adult Cane rats {1.8±0.7 kg body weights (bwt.)} assigned into group A (Female) and group B (Male) of three rats each was used for the study. Each animal was premedicated with atropine sulphate (0.05 mg/kg bwt), and later administered xylazine (10 mg/kg bwt) and ketamine (100 mg/kg bwt) intramuscularly. Meanwhile, anaesthetic characteristics and physiologic indices of anaesthesia were monitored.Results: Results obtained showed that the physiologic indices; open eyelids, smooth induction and recovery, skeletal muscle relaxation and somatic analgesia were observed in all the animals, however, the anaesthetic indices; time to induction, time to standing, duration of analgesia and duration of recumbency showed marked sex variations. The mean values for the duration of analgesia and recumbency were significantly elevated (P<0.05) in group B as compared with group A. Similar trend was seen for time to standing, but, it was non-significant (P>005). However, time to induction mean value for group A was non-significantly increased (P>005) when compared with group B. The heart rate, respiratory rate and rectal temperature mean values decreased in both groups non-significantly (P>0.05).Conclusion: Conclusively, the xylazine-ketamine combination produced anaesthesia in Cane rat and the combination is more tolerated in the male Cane rats than the female Cane rats

Development of Adaptive Sensing Algorithm for Minimizing Energy and Bandwidth Consumption in Cooperative Spectrum Sensing Technology

Optimized consumption of energy and bandwidth is crucial for efficient utilization of the limited electromagnetic spectrum for telecommunication purposes. Cognitive radio is one of the dynamic spectrum management applications with numerous benefits related to the management of available spectrum. But it has the challenge of high energy and bandwidth usage when the cooperative scheme of spectrum sensing is applied for accurate sensing. In this paper, an adaptive spectrum sensing algorithm was developed to minimize energy and bandwidth consumption in cognitive radio spectrum sensing while ensuring accurate spectrum sensing. The adaptive algorithm was developed based on the signal-to-noise ratio conditions of the channel. Results reveal that the energy and bandwidth usage by the cooperative spectrum sensing can be significantly reduced without negatively affecting the performance and detection of the cognitive radio in varying noisy condition

Optimizing Energy Utilization in Unequally Spaced Linear Array for Smart Antenna

Radiation in the form of unwanted patterns, energy wastage and reduction is caused by high side lobe levels in a radiation pattern. This, in turn, affects the overall performance of the antenna. The purpose of this work is to improve the performance of a smart antenna by optimizing the radiation pattern using the genetic algorithm. Optimal antenna parameters that would minimize side lobe level were obtained using genetic algorithm. Simulations were carried out to determine the impact of the increase in inter-element spacing on array factor and beamwidth using the optimal antenna parameters. The optimal arrangement of inter-element spacing and number of elements in unequally spaced antenna elements were then considered. The array factor model for a uniform linear array of elements was used to obtain the optimum weights that would give the desired radiation pattern with reduced side lobe level. Results for the unequally spaced linear arrays revealed that non-tapered arrangement among all the possible configurations gave the best improvement in the side lobe level. The outcome of this improvement is an optimized radiation pattern which is expected to aid the reduction of radiated power wasted in the side lobes of linear arrays in antenna systems

Farmers’ Behaviour towards Utilisation of Jatropha Curcas for Environmental Mitigation in Oyo State, Nigeria

The dysfunctional environment caused by soil erosion, wind erosion, deforestation, desertification, issues of flood was due to the effect of greenhouse gases emanating as a result of various activities of man and industries. Consequently, this has prompted the exploitation of Jatropha curcas for mitigating the environment. Therefore, this study was carried out to examine farmers’ behaviour towards utilisation of Jatropha curcas for mitigation of environment in the study area. A multistage sampling procedure was used in selecting 120 farmers from 217 trained Jatropha farmers across Ido and Akinyele Local Government Areas in Oyo State. The data was analysed using frequencies, percentages, mean scores, and pearson product moment correlation. The result for the study showed that majority of the respondents had mean age of 44.4± 10.8 with majority also being male (66.7%) and formal education (91.7%). The result revealed that there was significant relationship between socio-economic characteristics of the respondents and farmers’ behaviour towards utilization of Jatropha curcas for environmental mitigation. There was correlation between farmers’ awareness on cultivation of Jatropha curcas and their behavior towards utilisation of Jatropha curcas for environmental mitigation (r = 0.399**, p < 0.05). The respondents’ attitude was significantly related to their behavior towards utilization of Jatropha curcas for environmental mitigation (r = - 0.182*, p < 0.05). The study showed that awareness and attitude of farmers strongly influence their behaviour towards utilization of Jatropha curcas for environmental mitigation. The implication of this study is to ensure that the environment becomes free of hazards and degradation which affect survival of the ecosystem and biodiversity. Hence, government should join in the advocacy to open continuous channels of communication on the importance of Jatropha to motivate farmers to having right behaviour towards utilization of Jatropha curcas as a measure to mitigate the environment. Keywords: Behaviour, utilisation, Jatropha curcas, farmers, mitigation, environmen