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.     

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.     

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.     

An Additive Manufacturing Spare Parts Inventory Model for an Aviation Use Case

To maintain high service levels and mitigate long lead times, many enterprises hold large spare parts inventories. Using additive manufacturing (AM) for spare parts in aviation has been proposed previously but prior studies did not address system-specific lead time impacts. This article codifies lifecycle variables introduced by AM and presents an aviation case study. The variables highlight the value offered by AM over traditional methods. Specifically, the case study demonstrates that introducing up to 35% of AM parts to the spare parts inventory improves the system replenishment lead time by up to 33%, thus suggesting AM can be used to mitigate challenges related to spare parts management. This work also presents an approach to integrate AM into the spare parts inventory mix.     

Effect of Schiff Bases Containing Pyridyl Group as Corrosion Inhibitors for Low Carbon Steel in 0.1 M HCl

The inhibiting effect of four newly synthesised Schiff bases containing pyridyl group was investigated on the corrosion of low carbon steel in 0.1 M hydrochloric acid solution under various conditions by potentiodynamic polarisation method and impedance measurements. The Schiff bases used were 2-((1Z)-1-aza-2-(2-pyridyl)vinyl)benzene-1-thiol, (1Z)-1-aza-1,2- di(2-pyridyl)ethene, [((1Z)-1-aza-2-(2-pyridyl)vinyl)amino]benzene-1-thione and 2-((1Z)-1-aza-2-(2-pyridyl)vinyl)benzothiazole. All the Schiff bases inhibit corrosion of low carbon steel and their inhibition efficiencies increase with decrease in temperature and increase in concentration. The difference in protection actions of the inhibitors can be attributed to the presence of substituents in the structures that increase or decrease the electron density on the azomethine (–C=N–) group. Polarisation curves indicate that the Schiff bases act as anodic inhibitors. AC impedance and potentiodynamic polarisation measurements reveal that the compounds are adsorbed on the steel surface and the adsorption obeys the Temkin isotherm. Activation parameters (E_a, ΔH*, ΔS*) for the corrosion of low carbon steel in 0.1 M HCl were calculated and showed that corrosion was much reduced in the presence of inhibitors.     

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.     

Distance estimation of near‐field visual objects in stereoscopic displays

Stereoscopic displays have a promising future because of recent advancements and popularity of handheld devices and maturing head mounted displays. Gesture interaction such as pointing, selection, pinching, and manipulation are now possible in the current virtual environments, where accurate distance judgment is required. In this paper, we address the perception of exocentric distance in stereoscopic displays under two target orientations: horizontal and vertical. Three parallax conditions (on screen, 5 cm from screen, and 10 cm from screen) were considered, where the screen was fixed at a distance of 100 cm from the observer. Four levels of center‐to‐center distance between 10 and 50 cm were employed. The perceptual matching task revealed underestimation in all conditions. The overall judgment of exocentric distance was only about 80% of the actual. We also found a main effect of distance and interaction between layout and distance to be significant. The two important findings of this study are that underestimation of exocentric distance increases as the separation between virtual targets increases and that in vertical orientation, accuracy increases with closer targets. However, the main effects of layout and parallax on accuracy of judgment were not significant. Engineering implications of the results are also discussed in this paper.     

A Conceptual Framework for Increasing Innovation through Improved Selection of Specialized Professionals

Engineering managers involved in product development and manufacturing are responsible for proposing and developing ideas and concepts that will benefit new or existing products and processes. Improved methods are required to identify, prioritize, and integrate the opinions, ideas, and concepts proposed by specialized professionals (SP) or subject matter experts into their existing product development and process improvement. Identifying the optimal SPs and utilizing these for concept generation efforts can lead engineering management working in the new product/technology development space toward an improved idea/concept generation, increased innovation, and ultimately, superior products and processes. Methods for locating, assessing, and ranking SPs vary with every organization, but in general, systematic methods and processes are not considered, which results in the reliance on internal or limited external experts. This study aims to directly impact the engineering managers by bridging the gap between the traditional business management and core engineering management for providing guidance and improving the way in which the practicing engineering managers deal with new product development and management of technology. This experimental study is derived using a real-world engineering problem, which is faced in the field of engineering management, and the results support the implementation of a conceptual SP-focused framework that provides an increased quality of the concept generation outputs, improved preparation for future product development stages, and reduced costs.