Mechanical Properties of Heat-treated Medium Carbon Steel in Renewable and Biodegradable Oil

The heat treatment of steels under controlled conditions alters their physical and mechanical properties, enabling them to meet the desired engineering applications. In this study, the suitability of a Namibian local oil (marula oil) as an alternative quenchant to SAE40 engine oil (Standard quenchant – a synthetic oil derived from natural or crude oil) for industrial heat treatment of medium carbon steels was investigated. SAE40 engine oil served as the control. The mechanical properties (tensile strength, yield strength, percentage elongation and hardness) of the treated and untreated samples were investigated at the temperatures of 850oC, 900oC, 950oC and 1000oC. The untreated sample had the highest amount of elongation (40%), while the sample quenched in marula oil had the highest hardness (24.33HRD) and tensile strength (530.32 N/mm²) values compared with both the untreated and the SAE40 engine oil quenched samples. Hence, marula oil showed high potential as an alternative quenchant to petroleum based SAE40 engine oil for quenching medium carbon steels, without cracking or distortion

Detection and phenotypic characterization of methicillin-resistant Staphylococcus aureus from clinical and community samples in Abakaliki, Ebonyi State, Nigeria

Objective: The objective of this study was to isolate and phenotypically characterize methicillin-resistant Staphylococcus aureus (MRSA)from clinical and community samples in Abakaliki, Nigeria.Methods: A total of 709 clinical (303) and community samples (406) samples were obtained for this study. MRSA isolates were detected using Kirby-Bauer disc diffusion method with the inclusion of 1 μg oxacillin and cefoxitin antibiotic disc. The isolates were screened for the β-lactamase production using nitrocefin sticks.Results: A total of 44 MRSA isolates were obtained from the samples with prevalence frequency of 22.6 % and 20.8 % from clinical and community samples respectively. The clinical isolates were completely resistant (100 %) to ceftazidime, tetracycline and penicillin. Gentamicin and ciprofloxacin were the most effective antibiotics against the clinical and community isolates respectively with a susceptibility frequency of 63.2 % and 80 %. Exactly 38.1 % and 24.2 % of the clinical and community S. aureus isolates were positive for beta-lactamase production respectively. The HA-MRSA and CA-MRSA isolates had MARI valueswithin the range of 0.3 to 1.0.Conclusion: This present findings of multi-drug resistance MRSA is very worrisome as it further highlights the pressing need to keep a strict watch on MRSA emerging from this study area.Keywords: MRSA, beta-lactamase, antibiotics, multidrug resistance, clinical samples, community samples

Modelling and Analysis of Dynamic Stability of Glass Reinforced Plastic Pipes Subjected to Fluid Flow

In the past, almost every industry worldwide patronized iron and its alloys for every major industrial design, construction and other forms of work. However, with the advent of the Glass Reinforced Plastic (GRP) as accepted in the United Kingdom or the Fibre Reinforced Plastic as accepted in the United States, which was discovered in the nineteen thirty’s (1930’s), the Glass Reinforced Plastic (GRP) has become very versatile as it has become a household name in most industries globally .It has attained this height through the significant properties it possesses, which include its ability to transform into moulds of difficult and delicate shapes and sizes which iron and its alloy may not find easy to submit to. It brings a host of other benefits in the form of long term performance and reliability, ease of installation and the ability to withstand corrosion and tuberculation. A service life of more than thrice that of the ductile iron pipes to mention but a few. Ductile Iron pipes are used in most petrochemical industries where pipeline plays a very important role in transporting crude oil and gas. As the service duration increases, the pipe lines are affected by corrosion mechanism which can lead to fatal accident. Corrosion can occur at both the internal and external surface of the pipelines. In general, corrosion would cause metal loss which leads to reduction in pipeline thickness and consequently reduce its strength. It becomes necessary that the stability of the Glass Reinforced Plastic (GRP) pipes are carefully investigated especially in the event of high pressure turbulent flows. This is the thrust of this work. In the light of the above, ductile iron pipes and Glass Reinforced Plastics (GRP) pipes of the same thicknesses were investigated, some special characteristics such as the bursting pressures were calculated using Peter Barlow’s formula. The ANSYS software was also used for modal analysis and compare the stress profile under dynamic condition for both pipes. Also the cost of production of pipes, classification and the difficulties encountered during their installation processes were examined. The result indicated an overwhelming encouragement to use Glass Reinforced Plastic (GRP) pipes as substitutes to the traditional ductile iron and its alloys in view of the fact that Glass Reinforced Plastic (GRP) pipes withstand corrosion and tuberculation while saving the huge cost that would have been used for pigging &nbsp

Influence of Process Time on the Physicochemical, Antinutrient and Phytochemical Properties of Ficus capensis Moracae Vegetable Drink

Aims: To determine the best process time and processing duration effects on the composition of the Ficus capensis drink (infusion). Study Design:  Experimental design was based on completely randomized design (CRD). Methodology:  Ficus capensis (Moracae) leafy vegetable drink was processed by immersing the leaves in water (1:10) weight/liquid ratio. Three portions of samples were prepared and boiled separately in a stainless steel pot immersed in a water bath (temperature =100 oC) for 30, 60, and 90 min, respectively, and filtered. The samples were evaluated for proximate composition, minerals, phytochemicals, antinutrients, and physicochemical properties using standard methods.  Results: Protein, carbohydrate, and ash contents and energy value of the drink were affected differently by process times. Alkaloids, ascorbic acid, and calcium contents were lowest in samples processed by 90 min boiling. Drink processed by boiling the leaves for 60 min had the highest pro-vitamin A (12.51 mg/100ml), zinc (3.18 mg/100ml, flavonoid (18.4 g/100ml), and carotenoid (17.2 g/100ml), and 90 min processed drink had the highest vitamin B1 (0.35 mg/100ml) content. The iron contents ranged from 2.8-8.7 mg/100ml, and the values varied among different boiling times. Cyanide, phytate, and tannin contents decreased progressively as the processing times increased. Conclusion: The nutrient contents of Ficus capensis (Moracae) drink were affected by process time, however, boiling the leave for 60 min was established as the best process time for the  Ficus capensis vegetable drink processing

Techno-economic analysis of the statistically optimized biodiesel production process using African pear seed oil and activated empty palm fruit bunch biocatalyst

This research focuses on techno-economic analysis of the statistically optimized biodiesel production using African Pear Seed Oil and activated empty palm fruit bunch biocatalyst to ascertain the viability of producing African pear seed oil methyl ester (APSOME). Central composite design of response surface methodology (RSM) was used for the optimization of the process variables. The acid activated empty palm fruit bunch ash (AAEPFBA) catalyst used was synthesized from waste palm fruit bunch, and modified by adding H3PO4 acid in a ratio of 1:2 (g/ml). The RSM model predicted that the highest conversion yield of APSOME would be 89.3 %. The experiment performed yielded 90.1 %, which is in agreement with the predicted value at the following optimized reaction conditions: reaction temperature of 62.21 °C, time of 3.17 h, 10.2:1 methanol/oil molar ratio, 3.18 wt% catalyst concentration, and agitation speed of 326.51 rpm. It was established that the cost of labour will affect the profitability of produced APSOME. The overall result showed that AAEPFBA and APSO raw materials are viable and useful for sustainable biodiesel production

Transesterification of Persea americana seed oil to methyl ester using bio-based heterogeneous catalyst: Optimization and techno-economic analysis

The techno-economic analysis of producing biodiesel from agrarian wastes at optimal condition was carried out. The acid activated empty palm fruit bunch ash (AAEPFBA) catalyzed the methyl ester production. The AAEPFBA catalyst was synthesized from waste palm fruit bunch, and modified with phosphoric acid. The activation was best achieved by adding H3PO4 acid in a ratio of 1:2 (g/ml). The modification of the catalyst increased the alkaline properties and surface area and decreased the particle size and adsorption energy. The process variables of temperature 61.9 °C, reaction time of 3.09 h, methanol/oil molar ratio of 10.2:1, catalyst concentration of 3.14wt%, and agitation speed of 321.54 rpm at a desirability of one gave an experimental optimal yield of biodiesel as 90.3%. Based on the experimental study, 3062 litres (2728 kg) of biodiesel was evaluated annually. The annual operating cost, payback period, and internal rate of return are ₦2201288, 1.5 years, and 7.6%, respectively. The sensitivity analysis of oil purchase cost, biodiesel selling price, and labour cost on Return on investment, PBP, IRR, and Net present value were investigated. In this study, the relative biodiesel selling price is a determinant of the profitability of producing avocado pear seed oil methyl ester. The overall results show that investors can embark on biodiesel production using avocado pear seed oil, and AAEPFBA as feedstocks