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The purpose of this paper is to evaluate the protection against corrosion of carbon steel SAE 1020 promoted by a niobium- and titanium-based coating produced from a resin obtained by the Pechini method.

A resin was prepared with ammonium niobium oxalate as niobium precursor and K₂TiF₆ as titanium precursor. Carbon Steel SAE 1020 plates were dip coated in the resin and calcinated for 1 h at 600 ºC. Scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction were used to characterize the coating morphologically and structurally. Open circuit potential, electrochemical impedance spectroscopy, anodic potentiodynamic polarization and scanning vibrating electrode technique were used to evaluate the corrosion protection of the coating.

The electrochemical analyses evidence slight protection against corrosion of the coating by itself; however, the needle-like crystal structure obtained may potentially provide a good anchorage site, suggesting the coating could be used as a pretreatment that may present similar application to phosphating processes, generating lower environmental impacts.

Due to increasingly restrictive environmental laws, new environmentally friendlier surface treatments must be researched. This paper approaches this matter using a combination of niobium- and titanium-based coating, produced by a cleaner process, the Pechini method.

The purpose of the paper is to show the corrosion effect of benzotriazole in comparison with iron phosphate (PFe) coating as a sealer for the PFe layer in carbon steel paint pre-treatment and to show its ecological advantages as a more environment-friendly inhibiting compound than PFe.

Samples of carbon steel (SAE 1010) were phosphated in two baths, one containing iron PFe and PFe and BTAH (PFe + BTAH). Anodic potentiostatic polarization curves and electrochemical impedance spectroscopy were used to evaluate the corrosion resistance of phosphated carbon steel in 0.1 molL−1 H₂SO₄, 0.5 molL−1 NaCl and 0.1 molL−1 NaOH. The phosphate layers obtained were analyzed by infrared spectroscopy. Surface observation by scanning electron microscopy (SEM) showed that the PFe and PFe + BTAH layers are deposited as crystals with granular morphology. The electrochemical results showed that the PFe + BTAH coating was more effective in corrosion protection of the carbon steel.

This paper presents the application of benzotriazole as post-treatment of PFe-coated carbon steel. The results show that benzotriazole improves the phosphate layer properties. The SEM micrographs showed that the layer formed in PFe and PFe + BTAH baths consists of grain-like crystals, and infrared results revealed the BTAH presence in PFe phosphate. The corrosion resistance results showed higher efficiency associated to the PFe + BTAH phosphate layer relative to that of PFe. From the present study, results can be concluded that BTAH can be used as a post-treatment for PFe phosphate coating.

This paper deals with the corrosion resistance and surface carbon steel characterization of a new sealer for PFe coating, which has been prepared for this study and was never tested previously. These are candidate materials for substitution of chromium sealer. The BTAH sealer presents environmental and corrosion resistance advantages when compared with the post-treatment based on chrome. Although BTAH improves PFe layers’ properties, it is the worst phosphate coating. This manuscript has never been previously submitted and deals with original results.

The study aims to assess students' perceived mastery of reasoning-for-complexity competency and its sub-competencies in a sample of students in a Latin American university. The intention was to identify statistically significant differences between a population of men and women with similar sociocultural characteristics, assessing whether gender could be a factor for educational institutions to consider when implementing strategies to develop this competency.

The eComplexity instrument was applied to 370 undergraduate students in their first to ninth semesters in a private university in Western Mexico. Descriptive statistics were analyzed to determine the mean and standard deviation indicators and were tested for statistical significance. The convenience sampling methodology ensured that there were students from all semesters and a diversity of majors. The sampling aimed for a balance of men and women, resulting in 189 women and 181 men.

The results confirmed no statistically significant evidence to indicate differences between men and women in their perceived mastery of the reasoning-for-complexity competency in general. However, statistically significant differences were found in the perceived achievements of the sub-competencies of systems, critical and scientific thinking, which comprise the overall competency. Women presented a higher average perception of systemic and critical thinking achievement, and men had a higher perception of scientific thinking. The authors concluded that social and cultural elements influence the perception of achievement that men and women develop in thinking and solving problems.

Governments and educational institutions must establish training programs that do not follow gender stereotypes and promote reasoning-for-complexity skills equitably in men and women. It is necessary to create more scientific and academic spaces and projects involving women in the sciences; countries must emphasize this to improve their scientific competency. Only in this way will it be possible to reverse the perception that men and women have of their problem-solving skills and abilities, which, as this study shows, are more a matter of culture than capabilities.

Unlike previous studies, which analyze the competency of complex thinking in a particular way among its sub-competencies, this research sought comprehensive measurement. Furthermore, beyond measuring competency development, this study aimed to measure the perception of achievement. The authors believe this is the first step towards identifying elements of the social imagination that limit the formation of scientific thinking among women in Latin America.