Corrosion inhibition of stainless steel by polyaniline,poly(2-chloroaniline), and poly(aniline-co-2-chloroaniline) in HCl

Polyaniline (PANi), poly(2-chloroaniline) (PClANi), and poly(aniline-co-2-chloroaniline) (co-PClANi) films were synthesized by electrochemical deposition on 304-stainless steel (SS) from an acetonitrile solution. The structural properties of these polymer films were characterized by spectroscopic (FTIR and UV–vis) and electrochemical (cyclic voltammetry) methods. Open circuit potential–time (E_ocp–time) curves, potentiodynamic polarization, and electrochemical impedance (EIS) measurements showed that these films have significant protective performance against corrosion of SS in 0.5 M HCl solution. It was found that co-PClANi film has acted as a passivator as well as barrier for cathodic reduction reaction in a similar manner as PANi film. However, PClANi film has behaved only as barrier for corrosion protection of SS in 0.5 M HCl.     

Adsorption and inhibition effect of benzotriazole on brass-118 and brass-MM55 in artificial seawater

Corrosion behaviours of the new type special commercial brass alloys, called 118 and MM55, have been investigated by Tafel Extrapolation (TP) and Linear Polarization (LP) methods in artificial seawater. Inhibition effect of benzotrizole (BTA) of four different concentrations for the corrosion of brass samples was investigated. It was found that BTA was acting as mixed type inhibitor and inhibition efficiency was increasing with the increase of BTA concentration. The change of the degree of surface coverage (θ) as a function of inhibitor concentration (c) shows that BTA follows Langmuir adsorption isotherm. Values of adsorption equilibrium constants (K _ads) and values of free energies of adsorption (ΔG _ads) were calculated from adsorption isotherms. Results reveal that chemisorption is the initial step of inhibition processes.     

Controlling the phase behavior of block copolymers via sequential block growth

Block copolymers remain one of the most extensively investigated classes of polymers due to their abilities to self-organize into various nanostructures and modify polymer/polymer interfaces. Despite fundamental and technological interest in these materials, only a handful of experimental phase diagrams exist due to the laborious task of preparing such diagrams. In this work, two copolymer series are each synthesized from a single macromolecule via sequential living anionic polymerization to yield molecularly asymmetric diblock and triblock copolymers systematically varying in composition. The phase behavior and morphology of these copolymers are experimentally interrogated and quantitatively compared with predictions from mean-field theories, which probe copolymer phase behavior beyond current experimental conditions.     

Dynamic electrochemical impedance spectroscopy and polarization studies to evaluate the inhibition effect of benzotriazole on copper‐manganese‐aluminium alloy in artificial seawater

The effect of benzotriazole (BTA) on the corrosion of a new type copper‐manganese‐aluminium (CMA) alloy in artificial seawater was investigated using dynamic electrochemical impedance spectroscopy (DEIS), linear polarization resistance, and Tafel extrapolation methods. Measurement results obtained from those three methods showed that corrosion rates decreased while BTA concentration increased. This clearly indicates that BTA inhibits the corrosion rate of CMA in artificial seawater. Although there are consistent results obtained from all these three methods, the results of the percent inhibition efficiency, IE (%), values obtained from DEIS method should be calculated from the charge transfer resistance (R_ct) values obtained after 5 h.     

Use of Fourier transform infrared spectroscopy for rapid comparative analysis of Bacillus and Micrococcus isolates

The identification of foodborne microorganisms and their endospores in food products are important for food safety. The present work compares Bacillus (Bacillus licheniformis, Bacillus circulans and Bacillus subtilis) and Micrococcus (Micrococcus luteus) species with Fourier transform infrared (FTIR) spectroscopy. Our results show that there are several characteristic peaks belonging to both the Micrococcus and Bacillus species which can be used for the identification of these foodborne bacteria and their endospores. For Micrococcus species, a new band was observed at 1338 cm⁻¹ which may be due to acetate oxidation via the carboxylic acid cycle. The bands at 1313 cm⁻¹ and 1256 cm⁻¹ can be explained by an exopolymer formation and the other bands at 1074 cm⁻¹ and 550 cm⁻¹, may be due to the glycogen-like storage material in Micrococcus spp. There are also characteristic peaks at 993 cm⁻¹ and 801 cm⁻¹ for these bacterial species. Different Bacillus species also showed characteristic peaks at 1000–500 cm⁻¹ region. Dipicolinic acid (DPA) bands at ∼728 cm⁻¹ and ∼703 cm⁻¹ seen only in B. circulans were the marker of an endospore formation.     

Best management practices for corporate, academic and governmental transfer of sustainable technologies to developing countries

Innovations with respect to technologies that contribute to environmental sustainability have emerged within national government laboratories, international agencies and within academic research institutes. Since each of these entities is understandably more focused on ab initio research, conceptual development and proofs of concept, the production level manufacturing and broad dissemination of such technologies require development of best management practices (BMPs) for effective partnerships with and/or technology licensure to private sector industry. Alternatively, certain technologies that address specific environmental sustainability needs within the developing countries can be and have been transferred directly, either through bi-lateral transfers or through multi-lateral agencies, serving as intermediaries. The appropriateness of such transfers is contingent upon host country environmental, cultural and socio-political conditions, the type of technology involved, the “terms of transfer” and the relationships established between the technology conceivers and the end-users. The authors select examples of identified modes of sustainable technology transmission and derive experiential BMPs, which may be of some utility for future sustainable technology transfer. Moreover, in providing these BMPs, the historical record and contemporary caveats with respect to unregulated technology transfer, whether sustainable or otherwise, to developing countries and the array of corresponding proposed codes of conduct are examined, given the normative objective that such technologies should ultimately contribute to ecologically benign and societally beneficial objectives, such as environmental sustainability, equitable growth and poverty alleviation. These issues and the need to establish BMPs would be broadly relevant with the new focus on climate change-related technology funds and associated regional impact projects evolving across the globe and within the developing countries in particular.     

The accuracy of distance perception in the frontal plane of projection‐based stereoscopic environments

An experiment was conducted to investigate the accuracy of distance judgment in a frontal plane of projection‐based stereoscopic environments. The targets were presented at nine distinct frontal plane positions and at three depth levels. Eighteen right‐handed participants with self‐declared normal visual acuity reached the target, either continuously visible or presented briefly, by holding pointing sticks. All combinations of the experimental conditions were repeated for an equivalent real‐world environment. Accuracies of judgments were then computed from three‐dimensional data collected by a motion system composed of six infrared cameras. As compared with about 94% accuracy in the physical world, the space in the frontal plane was only about 85% on the stereoscopic environment. The result also revealed more accurate judgment in the continuous presence of the target. Furthermore, the accuracy was affected by the egocentric distance of the frontal plane from the position of the participant. The study concluded that the compression in the frontal plane and underestimation of depth, which has been reported by the majority of previous studies could be an indication that the space compression in virtual environments might be in all the three‐dimensions. These findings can be used as guidelines for developers and content designers to properly locate virtual targets and selection of efficient interaction modes.