BIODIESEL PRODUCTION BY ESTERIFICATION OF OLEIC ACID WITH ETHANOL UNDER ULTRASONIC IRRADIATION

Joint Research on Environmental Science and Technology for the Eart

The environment-induced cracking of as-annealed Ni3(Si,Ti) and Ni3(Si,Ti) with 2Mo in sodium chloride solutions

Accepted manuscript version. The final publication is available at Springer via http://doi.org/10.1186/s40712-015-0046-7.Background The environment-induced cracking (EIC) of as-annealed Ni3(Si,Ti) and Ni3(Si,Ti) with 2Mo has been researched as functions of applied stress, chloride ion concentration, test temperature, and pH. Methods The investigation of EIC was carried out by applying a constant method in NaCl solutions. Results The EIC susceptibility of both intermetallic compounds increased with increasing test temperature and Cl− ion concentration and increased with decreasing pH. The fracture surface morphologies of Ni3(Si,Ti) was intergranular while Ni3(Si,Ti) with 2Mo was a mixture of intergranular and transgranular, and the relationship between log t f (time to failure) and log l ss (steady-state elongation rate) became the identical straight line irrespective of applied stress, chloride ion concentration, test temperature, and pH, which means that l ss becomes a relevant parameter for predicting t f. The EIC susceptibility of Ni3(Si,Ti) with 2Mo was lower than that of Ni3(Si,Ti), which showed the advantageous effect of Mo. Conclusions From the results acquired, EIC of both the compounds was indicated to take place by hydrogen embrittlement (HE)

DRY DEPOSITION MONITORING IN VIETNAM AND REMOVAL OF AIR POLLUTANTS BY USING BIODIESEL FUEL

Joint Research on Environmental Science and Technology for the Eart

The Effect of Applied Stress on Environment-Induced Cracking of Aluminum Alloy 5052-H3 in 0.5 M NaCl Solution

The environment-induced cracking (EIC) of aluminum alloy 5052-H3 was investigated as a function of applied stress and orientation (Longitudinal rolling direction—Transverse: LT and Transverse—Longitudinal rolling direction: TL) in 0.5 M sodium chloride solution (NaCl) using a constant load method. The applied stress dependence of the three parameters (time to failure; tf, steady-state elongation rate, Iss, and transition time at which a linear increase in elongation starts to deviate, tss) obtained from the corrosion elongation curve showed that these relationships were divided into three regions, the stress-dominated region, the EIC- dominated region, and the corrosion-dominated region. Aluminum alloy 5052-H3 with both orientations showed the same EIC behavior. The value of tss/tf in the EIC-dominated region was almost constant with 0.57±0.02 independent of applied stress and orientation. The fracture mode was transgranular for 5052-H3 with both orientations in the EIC-dominated region. The relationships between log Iss and log tf for 5052-H3 in the EIC-dominated region became a good straight line with a slope of −2 independent of orientation

The effects of film thickness and incorporated anions on pitting corrosion of aluminum with barrier-type oxide films formed in neutral borate and phosphate electrolytes

The pitting corrosion behavior of high-purity aluminum covered with barrier-type anodic films, which are formed in neutral borate and phosphate electrolytes, has been examined in 0.5 mol dm(-3) NaCl solution at an applied potential of -0.6 V versus Ag/AgCl, which is slightly nobler than the pitting potential of -0.64 V in the same solution. The pitting current density, i (p), increased with time after an incubation time, t (i). The double logarithmic plot of i (p) and polarization time, t, reveal two straight lines, which are separated at the time, tau. The slope becomes larger after tau for the specimens anodized in the phosphate electrolyte, while it becomes smaller for those in the borate electrolyte. Both the t (i) and tau increase with the thickness of the anodic films, and at the similar film thickness, they are much larger for the anodic films formed in the phosphate electrolyte than for those in the borate electrolyte. The corrosion process can be divided into three stages: the incubation period up to t (i), the pit nucleation period before tau, and the pit growth period after tau. We have discussed the different pitting corrosion behavior of the aluminum specimens covered with the anodic films formed in the borate and phosphate electrolytes in terms of ion selectivity of the anodic films