Comparative Assessment of the Fracture Behaviour of API‐5L X65 and Micro‐alloyed Steels in E80 Simulated Fuel Ethanol Environment

Monotonic J‐integral tests were carried out on API‐5L X65 steel and micro‐alloyed steel (MAS) in E80 simulated fuel grade ethanol (SFGE) environment using three‐point bend specimens. A ramp rate of 10-04 mm/s was used for loading in each sequence so as to enhance stress corrosion cracking (SCC) influence if any. The influence of the SFGE environment on tearing resistance and fracture toughness of the steels was studied. Both steels exhibited decrease in fracture toughness in E80 in relation to air. The decrease in fracture toughness may be due to anodic dissolution at the crack tip. Ductile tearing resistance of the steels increased in E80 due to decline in toughness property. In comparison with X65 steel, MAS showed better fracture properties

Evaluation of dum palm kernel activated carbon in chromium and lead adsorption from synthetic waste water

This study aimed at the co-current removal of chromium and lead ions from synthetic waste water using dum palm kernel activated carbon. The adsorption experiment was conducted by varying time, pH and concentrations of the simulated solution. The data obtained were analyzed, and the best conditions for the uptake were at pH of 6, equilibrium time of 40 minutes. The two best isotherms models for the adsorption system were Sip, and Dubinin–Radushkevich, models respectively. Based on the Temkin adsorption energy calculated as 9.5793 and 0.4997 J/mol, the uptake of lead and chromium were chemisorption and physico-sorption, respectively. The maximum uptake calculated from Dubinin–Radushkevich plots were 14.1696 and 7.7191 mg/g, for lead and chromium, respectively.International Journal of Environment Vol.5(3) 2016, pp.104-118</p

The kinetics of glucose production from rice straw by Aspergillus niger

In this investigation, glucose was produced from rice straw using cells of Aspergillus niger, isolated from maize grain. Glucose yield was found to increase from 43 to 87% as the rice straw particle size decreased from 425 to 75 ìm, while the optimal temperature and pH were found within the range of 45 - 50°C and 4.5 - 5 respectively. The concentration and rate of glucose production was observed to depend on pretreatment of rice straw, substrate concentration and cell loading. A kinetic model rateexpression has been developed for such a process based on the Michaelis – Mentens and Lineweaver – Burk approach. Comparison between the experimental data and those predicted from the rate model indicate good agreement with a mean absolute deviation of about 0.2