Preliminary Investigation of the Corrosion Behavior of Proprietary Micro-alloyed Steels in Aerated and Deaerated Brine Solutions

The corrosion performance of fairly new generation of micro-alloyed steels was compared in different concentrations of aerated and deaerated brines. Electrochemical polarization, weight loss and surface analyses techniques were employed. The results showed a threshold of corrosion rate at 3.5 wt.% NaCl in both aerated and deaerated solutions. The average corrosion current density for steel B, for example, increased from 1.3 µA cm¯² in 1 wt.% NaCl to 1.5 µA cm¯² in 3.5 wt.% NaCl, but decreased to 1.4 µA cm¯² in 10 wt.% deaerated NaCl solutions. The aerated solutions exhibited an average of over 80% increase in corrosion current density in the respective concentrations when compared with the deaerated solution. These results can be attributed to the effects of dissolved oxygen (DO) which has a maximum solubility in 3.5 wt.% NaCl. DO as a depolarizer and electron acceptor in cathodic reactions accelerates anodic metal dissolution. The difference in carbon content and microstructures occasioned by thermo-mechanical treatment contributed to the witnessed variation in corrosion performance of the steels. Specifically, the results of the various corrosion techniques corroborated each other and showed that the corrosion rate of the micro-alloyed steels can be ranked as CR[Steel A] < CRₓ₆₅ < CR[Steel B] < CR[Steel C]

Shoot regeneration, biochemical, molecular and phytochemical investigation of Arum palaestinum Boiss

Arum palaestinum Boiss. populations are in danger of extinction in the wild. Thus, there is a need to establish a reliable strategy for multiplying this valuable medicinal plant. In the present study, seeds and tissue culture of A. palaestinum were subjected to biochemical, molecular and phytochemical analysis. Obtained results indicated that the best medium for shoots proliferation was Murashige and Skoog (MS) medium supplemented with 5 mg/L benzyl adenine (BA) and 0.1 mg/L naphthalene acetic acid (NAA). The regenerated shoots were rooted on half strength MS medium containing 1 mg/L NAA and 2 g/L charcoal. Tissue culture derived plantlets were successfully acclimatized under ex vitro conditions. Protein analysis referred that, the difference in protein profiles in the examined samples suggests that a real genetic change might have occurred. Obtained results of the inter simple sequence repeat (ISSR) revealed variation between the regenerated plants and mother plant while the phytochemical investigation revealed that, 10 phenolic compounds (seven flavones, one flavonol and two phenolic acids) were identified using HPLC analysis and five compounds were detected in the plant for the first time. Genetic characterization and chemical investigation of seeds and in vitro cultures reported herein, is the first report for A. palaestinum.Keywords: Black calla lily, in vitro culture, inter simple sequence repeat (ISSR), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), isozyme, phenolic compounds.African Journal of Biotechnology, Vol 13(31) 3522-353