Effect of Coolant Temperature on Machining Characteristics of High Carbon Steel

This paper reports on the effect of coolant temperature on machining of high carbon steels. The development of a cooling system to reduce the temperature of water soluble coolant to 7.9oC from ambient temperature was employed in this work to improve the machining performance. The experiments were performed using cooled and ambient temperatures by employing Taguchi L18 orthogonal array to design the experimental runs. The cutting speed, feed rate and depth of cut were the machining parameters used; while the tool-work piece interface temperature was monitored using a digital thermometer with k-type thermocouple wire. The selected control factors are material removal rate and surface roughness. The experimental results were analyzed using Minitab 16. The main effects and percentage contributions of various parameters affecting surface roughness and material removal rate were discussed, and the optimal cutting conditions were determined. It was observed that surface finish improved by 65% with the use of the developed cooled system. The reduction in coolant temperature played a vital role in improving surface finish during machining high carbon steels

Nigeria’s Phosphate and Uranium Mineral Occurrences: Implication for Mineral Investment

The main aim of this paper is to review the occurrences of phosphate and uranium in Nigeria with a view to encourage local and international investors to develop and exploit these deposits. Nigeria is located on latitude 100 North and longitude 80 East surrounded in the north by Niger and Chad and in the east by Cameroun and in the west by Benin Republic. Available data indicated the viability of mineral investment in the Nigerian phosphate and uranium resources. With the current economic reforms and investment incentives in Nigeria, interested investors are highly welcome to take advantage of developing these mineral resources. Keywords: phosphate, uranium, mineral resources, mineral investment, geochemical mappin

Effect of Weed Control Methods and Canopy Characteristics on Weed Biomass, Yield and Yield Components of Two Contrasting Cassava Varieties in the Rainforest Zone of Nigeria

Weed infestation is one of the reasons why the average cassava yield is low in Nigeria. This study was conducted in 2010 at the Teaching and Research Farm, Obafemi Awolowo University, Ile-Ife to evaluate the impact of different cassava canopy structures on (i) weed biomass and (ii) yield and its components. The treatments consist of hand-weeded, herbicidal treatment, and unweeded checks in the main plot. The sub-plots constituted the cassava cultivars (TMS 30572 and TME 1) laid out in a randomized complete block with a split-plot arrangement in three replications. TMS 30572 reduced weed biomass by 59% when compared to TME 1 in the unweeded plot. However, there was no significant difference in the weed biomass between the hand-weeded and herbicide-treated where TMS 30572 and TME 1 were cultivated. Root dry matter of TMS 30572 was higher by 72% when compared to TME 1 in the untreated field. However, there was no significant difference between the yield of TMS 30572 and TME 1 in both hand-weeded and herbicide-treated plots. In conclusion, TME 30572 is recommended for cultivation in regions with similar agroecological patterns coupled with Integrated Weed Management (IWM) especially, when planting TME 1 to obtain optimum yield. Keywords: Weed biomass, TMS 30572, TME 1, Yield, and Integrated Weed Management. DOI: 10.7176/JNSR/12-14-05 Publication date:July 31st 202

Evaluation of two contrasting cassava canopy structures on weed flora composition in a rainforest zone of Nigeria.

The impact of weed competition on crop growth is a universal concern to farmers. This study was conducted in 2010 at the Teaching and Research Farm, Obafemi Awolowo University, Ile-Ife to evaluate the impact of cassava canopy on weed diversity and identify shade-tolerant weed species in response to varying canopy structure at Obafemi Awolowo University Teaching and Research Farm, Ile-Ife ecological zone. The treatments consist of hand-weeded, herbicidal treatment, and unweeded checks in the main plot. The sub-plots constituted the cassava cultivars (TMS 30572 and TME 1) laid out in a randomized complete block with a split-plot arrangement in three replications. Fifteen weed species survived under the shade of TMS 30572 where two families were monocots while four families were dicots. However, twenty weed species were recorded where TME 1 was cultivated of which two families were monocots while five families were dicots. TMS 30572 suppressed weeds by 20% when compared to TME 1. In conclusion, TME 30572 is recommended for cultivation in this agroecology to obtain a maximum benefit on cassava production. Keywords: Weed, TMS 30572, TME 1, Shade-tolerant, and Weed diversity. DOI: 10.7176/JNSR/12-12-05 Publication date:June 30th 202

Comparative Analysis of Selected Animal and Vegetable Oils Suitability in Machining of Plain Carbon Steels

Due to the alarming rate in public awareness on environmental issues, there has been growing demand for biodegradable materials which has opened an avenue for using vegetable and animal oils as alternatives to petroleumbased polymeric materials in the market, most especially in machining operations. Thus, research on biodegradable functional fluids has emerged as one of the top priorities in lubrication, due to their applicability in many diverse areas. In this quest, there is need to conduct machining trials to determine the suitability of these oils in metal cutting (turning) operations of plain carbon steels. This study investigate the effect of the selected cutting fluids on certain parameters like machine removal rate (MRR), machining time, tool wear and spindle power consumption, etc. under different machining combination in turning operations of plain carbon steels obtained from universal steel Ikeja, Nigeria, using 150 x 10 HSS cutting tool. The selected oils purchased from Ogunpa market in Ibadan, Nigeria, were sieved to remove any foreign particles or dirt. The solution; water, based-oil, and emulsifier (to allow thorough mixing of water and oil without separation), were mix at an elevated temperature of 550C in a proportion 4:1:3. Experimental results clearly showed that Conventional cutting fluid might be replaced with Non-conventional cutting fluids (vegetable and animal based) as they give better performance. With slight modifications and deliberate but careful alterations in some of the components of such oils, even better performing cutting fluids could be obtained.Self-sponsore

Impaired expression of testicular androgen receptor and collagen fibers in the testis of diabetic rats under HAART: the role of Hypoxis hemerocallidea

Introduction. Wide spectrum of alterations associated with highly active antiretroviral therapy (HAART) has been reported. The current study aimed at evaluating the role of Hypoxis hemerocallidea (HH) aqueous extract on the testosterone levels, expression of androgen receptors and collagen fibers in the testes of streptozoto­cin-nicotinamide-induced diabetic rats under HAART regimen. Material and methods. Sixty two adult male Sprague-Dawley rats (189.0 ± 4.5 g) were divided into eight groups (8 animals in each treatment groups and 6 rats in the control group). Diabetes was induced by a single intraperi­toneal injection of nicotinamide (110 mg/kg bw) followed by streptozotocin (45 mg/kg bw) and the animals were then subjected to various treatments with HAART, HH extract or melatonin. At the end of the experiment, blood samples were collected to measure serum testosterone levels. Testes were fixed in buffered formaldehyde and paraffin processed. The expression of androgen receptor (AR) was assessed by immunohistochemistry and collagen fibers were visualized by Masson trichrome staining. Results. Serum testosterone level was drastically (p < 0.0001) reduced in all rats with induced diabetes. In the testis of diabetic rats increased collagen fibers deposition with varying derangements in germinal epithelium of spermatogenic layers were observed. Intertubular hemorrhages and absence of spermatozoa were also noted in the testes of diabetic rats subjected to HAART. Reduced immunoexpression of ARs was found in the nuclei of Sertoli cells and the cytoplasm of spermatogonia and spermatocytes in III–IV stages of the seminiferous epithelium cycle of diabetic animals treated with different dosages of HH alone and those treated with HAART concomitantly with melatonin and HH. The expression of ARs was almost negative in the testes of rats treated with HAART alone. Conclusions. Concomitant treatment of rats with aqueous HH extract during the HAART did not change se­rum testosterone level nor mitigate the altered expression of collagen fibers and androgen receptor resulting from STZ-nicotinamide-induced diabetes. Therefore, anti-diabetic properties of Hypoxis extract require further investigation

Determination of Crop Coefficient and Water Use of SUWAN-1-SR with a Mini Lysimeter in Ibadan, Nigeria

Accurate irrigation planning requires basic information about the soil, environment and the water requirements of the crop to be cultivated. With new variety of a crop comes the physiological characteristics that may be somewhat different from known varieties. Crop Water Requirement (CWR) and Crop Coefficient (Kc) are major factors required in irrigation planning and they vary with crop developmental stages. Four non-weighing Lysimeters (Diameter, 60cm and Depth, 50cm) were used to determine CWR, Kc as well as crop performances under specific conditions. The CWR and Kc of Maize variety (SUWAN-1-SR) were determined across the four developmental stages (Initial, Development, Mid and Late) using the lysimeter system.  The CWR were 58.8, 176.8, 206.0, 59.6 mm and Kc were 1.0, 1.6, 1.4, 0.7 for the respective stages.  In comparison with FAO 56 maize Kc and CWRvalues, SUWAN-1-SR requires more water across the developmental stages and a sum of 501.2mm for the crop cycle. The average yield was 14.1t/ha, while average Water Use Efficiency (WUE) in the Lysimeter plots was 2.68±0.44 kg/m3 at a planting spacing of 40cm x 40cm, The WUE is high confirming the yielding potential of SUWAN-1-SRif given necessary nutrient inputs, and water requirement met. The developed lysimeter can be used to efficiently determine CWR. Keywords -Lysimeter, Crop Coefficient, Crop Water Requirement,  SUWAN-1-SR maize variet

Effectiveness of Moringa Oleifera and Blends of Both Alum and Moringa as Coagulant in the Treatment of Dairy Wastewater.

. Food processing industries can cause some serious problems for the environment through the discharge of wastewater. There is little information on the effectiveness of Moringa Oleifera (MO)seeds on the treatment of dairy wastewater, this study therefore evaluated the effectiveness of MO seeds and blends of both alum and MO in the coagulation of diary wastewater. Wastewater collected from oriental food industry limited was kept in a 10L capacity plastic container covered using a black polyethene bag containing ice blocks and conveyed to the laboratory where it was kept in a refrigerator. Six different beakers (Nos 0-5) were filled with 200 mL of wastewater and different doses of the selected coagulant (alum, MO and a blend of both) was added to the six beakers ranging from 0-10mL at an increment of 2mL to treat the wastewater. The beaker with number 0 served as the control (no dosage) and this whole process was applied to both coagulants. This test was carried out at a settling time of 1 hour. The physicochemical characteristics of the treated dairy wastewater were determined using the standard methods. Data were analyzed using descriptive statistics and ANOVA. The analysis indicated that the raw wastewater had values of 932 NTU, 1690.99 mg/L, 7.2 and 685 mg/L for turbidity, BOD, pH and TSS respectively. The results revealed that at an optimum dosage and settling time of 10mL and 1hr respectively, the TSS removal efficiencies of 88.76, 82.63 and 86.42 % were obtained for blend of moringa and alum, alum and moringa respectively. The three types of coagulants did not have much effects on the BOD and there were no significant differences in the values. The use of the blend of moringa and alum is effective in the treatment of dairy wastewater

Development and Evaluation of an Interactive Instructional Package for Teaching Engineering Graphics Skills

Exposure to modern pedagogical approaches and methods with appropriate instructional media can enhance the development of high-level critical thinking and technical skills. This study examined the development of an interactive instructional software package for teaching engineering graphics and evaluated its relative effectiveness on second-year undergraduate engineering students' academic achievement, skill transfer, and retention. In this study, the quasi-experimental, pre-test, post-test, control group design was employed. 45 research participants were sampled, employing two-stage stratified sampling technique, which comprises the simple random sampling to assign students into three groups from the study population and systematic sampling with k = 3 to select 15 students from each group to a control group and experimental groups A and B. The control group was exposed to conventional classroom instruction (CI), group A to computer-aided instruction (CAI); and group B to conventional and computer-aided instructions (CCAIs). A computer-aided learning package on engineering graphics was developed using the Camtasia software package, which served as the treatment instrument. The pre-test and post-test data used for analysis stemmed from a validated Engineering Graphics Achievement Test instrument. Analysis of covariance and Sidak post hoc test statistical analysis of the groups' performance provided the results on the comparative effects of the treatment conditions. Findings indicated significant differences between the academic achievement, skill transfer, and retention of students, exposed to CCAIs, and CI or CAI strategies. When used together, a significant improvement in students' academic achievement, transfer, and retention of engineering graphics skills occurred than either the CI or CAI strategy used alone