For carbon steels immersed in CO2 saturated solutions at different temperatures, the structure and the composition of corrosion product film formed on the steel surface were studied by scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The corrosion rate of the steel was evaluated by potentiodynamic polarization, and the relation between the corrosion rate and the film property was discussed. The corrosion rate of the steel was very closely associated with the structure and the composition of corrosion product film, which were affected significantly by the solution temperature. From 30 to 60 ºC, the corrosion product film composed of FeCO3 was porous and poorly adherent, and the corrosion rate increased with the rise of temperature. At 70 and 80 ºC, the corrosion product film was also composed of FeCO3 and presented a compact and dense cubic crystal structure, resulting in the decrease on the corrosion rate. The corrosion rate increased once again when the temperature was up to 90 ºC, which was attributed to the negative effect of high temperature water vapor corrosion on the grain coarsening and the part exfoliation for the FeCO3 film.

Background: Introgression of transgenes from crops to their wild species may enhance the adaptive advantage and therefore the invasiveness of and weedy forms. The study evaluated the effect of Africa Biofortified Sorghum (ABS) genes from ABS event 188 on the vegetative and reproductive features of the F2 populations derived from crosses with Sorghum bicolor subsp. drummondii. Results: F1 populations were obtained from reciprocal crosses involving ABS event 188 and its null segregant with inbred weedy parents from S. bicolor subsp. drummondii. Four F2 populations and four parental populations were raised in RCBD with 4 replications in a confined field plot for two seasons. Vegetative and reproductive traits were evaluated. The vigour shown in the F2 populations from the reciprocal crosses involving ABS event 188 and S. bicolor subsp. drummondii was similar to that in the crosses involving the null segregant and S. bicolor subsp. drummondii. Differences in vegetative and reproductive parameters were observed between the parental controls and the F2 populations. Examination of the above and below ground vegetative biomass showed lack of novel weedy related features like rhizomes. Conclusions: Therefore, release of crops with ABS 188 transgenes into cropping systems is not likely to pose a risk of conferring additional adaptive advantage in the introgressing populations. The interaction of ABS genes in weedy backgrounds will also not have an effect towards enhancing the weedy features in these populations.

<p>The inhibition mechanism of sodium oleate (C₁₇H₃₃COONa) for pitting corrosion of aluminum alloy (AA) 2024 in 0.1 mol L^-1 NaCl solution was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy with energy dispersive spectrometer (SEM-EDS) and X-ray photoelectron spectroscopy (XPS). C₁₇H₃₃COONa showed good inhibition effect on uniform corrosion of AA2024 in 0.1 mol L^-1 NaCl solution by promoting surface passivity of aluminum alloy. But in NaCl solution with high concentration (3.5 wt.% NaCl), C₁₇H₃₃COONa could not promote passivity of aluminum alloy. C₁₇H₃₃COONa also suppressed the tendency of pitting initiation and reduced the pitting corrosion sensitivity of aluminum alloy. The addition of 0.1 g L^-1 C₁₇H₃₃COONa showed good inhibition performance but further concentration increase had little effect on the inhibition efficiency. The C₁₇H₃₃COO− groups adsorbed on the surface of aluminum alloy by chemical adsorption effect, which promoted oxidation of the aluminum alloy surface.</p>

O processo de passivação de aço carbono durante deformação plástica em uma solução simulada de poro foi estudado usando-se testes eletroquímicos e microscopia de força atômica (AFM). Os resultados de polarização mostram que a atividade do aço carbono aumentou com o aumento do grau de deformação. Antes da ruptura dos filmes passivos, as amostras altamente deformadas apresentaram um alto potencial de circuito aberto (OCP). Por outro lado, o tempo de incubação de pite diminuiu com o aumento da deformação plástica. Os resultados de Mott-Schottky sugerem que a grande deformação tornou altamente dopados os filmes passivos. Além disso, as camadas de cargas espaciais dos filmes passivos afinaram quando a deformação plástica aumentou. As observações por AFM indicaram que os filmes passivos se tornariam menos homogêneos com aumento da deformação. Estes resultados demonstram que filmes passivos em aço carbono deformado se tornam instáveis quando a deformação plástica aumenta.

The process of passivation of carbon steel when experiencing plastic deformation in simulated pore solution has been studied using electrochemical tests and atomic force microscopy (AFM). The polarization results show that the activity of the carbon steel increased with increasing degree of deformation. Before the passive films were ruptured, the heavily deformed samples presented a high open circuit potential (OCP). On the other hand, the pitting incubation time decreased with increasing plastic deformation. The Mott-Schottky results suggested that the high deformation caused the passive films to be heavily doped. In addition, the space charge layers of passive films were thinned when the plastic deformation increased. The AFM observations indicated that the passive films become more inhomogeneous as the deformation increased. These results demonstrate that passive films on the deformed carbon steel become unstable when the plastic deformation increases.