Beyond prejudice: Are negative evaluations the problem and is getting us to like one another more the solution?

publication-status: Acceptedtypes: ArticleThis is a post print version of an article published in Behavioral and Brain Sciences, 2012, 35 (6), pp 438-439 DOI: http://dx.doi.org/10.1017/S0140525X12001252 Copyright © Cambridge University Press 2012For most of the history of prejudice research, negativity has been treated as its emotional and cognitive signature, a conception that continues to dominate work on the topic. By this definition, prejudice occurs when we dislike or derogate members of other groups. Recent research, however, has highlighted the need for a more nuanced and ‘inclusive’ (Eagly 2004) perspective on the role of intergroup emotions and beliefs in sustaining discrimination. On the one hand, several independent lines of research have shown that unequal intergroup relations are often marked by attitudinal complexity, with positive responses such as affection and admiration mingling with negative responses such as contempt and resentment. Simple antipathy is the exception rather than the rule. On the other hand, there is mounting evidence that nurturing bonds of affection between the advantaged and the disadvantaged sometimes entrenches rather than disrupts wider patterns of discrimination. Notably, prejudice reduction interventions may have ironic effects on the political attitudes of the historically disadvantaged, decreasing their perceptions of injustice and willingness to engage in collective action to transform social inequalities. These developments raise a number of important questions. Has the time come to challenge the assumption that negative evaluations are inevitably the cognitive and affective hallmarks of discrimination? Is the orthodox concept of prejudice in danger of side-tracking, if not obstructing, progress towards social justice in a fuller sense? What are the prospects for reconciling a prejudice reduction model of change, designed to get people to like one another more, with a collective action model of change, designed to ignite struggles to achieve intergroup equality

Energy and force analysis of Ti-6Al-4V linear friction welds for computational modeling input and validation data

The linear friction welding (LFW) process is finding increasing use as a manufacturing technology for the production of titanium alloy Ti-6Al-4V aerospace components. Computational models give an insight into the process, however, there is limited experimental data that can be used for either modeling inputs or validation. To address this problem, a design of experiments approach was used to investigate the influence of the LFW process inputs on various outputs for experimental Ti-6Al-4V welds. The finite element analysis software DEFORM was also used in conjunction with the experimental findings to investigate the heating of the workpieces. Key findings showed that the average interface force and coefficient of friction during each phase of the process were insensitive to the rubbing velocity; the coefficient of friction was not coulombic and varied between 0.3 and 1.3 depending on the process conditions; and the interface of the workpieces reached a temperature of approximately approximately 1273 K (1000 °C) at the end of phase 1. This work has enabled a greater insight into the underlying process physics and will aid future modeling investigations.EPSRC, Boeing Company, Welding Institut

High-throughput electrochemical sensing platform for screening nanomaterial-biomembrane interactions

A high-throughput, automated screening platform has been developed for the assessment of biological membrane damage caused by nanomaterials. Membrane damage is detected using the technique of analyzing capacitance–current peak changes obtained through rapid cyclic voltammetry measurements of a phospholipid self-assembled monolayer formed on a mercury film deposited onto a microfabricated platinum electrode after the interaction of a biomembrane-active species. To significantly improve wider usability of the screening technique, a compact, high-throughput screening platform was designed, integrating the monolayer-supporting microfabricated electrode into a microfluidic flow cell, with bespoke pumps used for precise, automated control of fluid flow. Chlorpromazine, a tricyclic antidepressant, and a citrate-coated 50 nm diameter gold nanomaterial (AuNM) were screened to successfully demonstrate the platform’s viability for high-throughput screening. Chlorpromazine and the AuNM showed interactions with a 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) monolayer at concentrations in excess of 1 µmol dm−3. Biological validity of the electrochemically measured interaction of chlorpromazine with DOPC monolayers was confirmed through quantitative comparisons with HepG2 and A549 cytotoxicity assays. The platform also demonstrated desirable performance for high-throughput screening, with membrane interactions detected in <6 min per assay. Automation contributed to this significantly by reducing the required operating skill level when using the technique and minimizing fluid consumption

Magnesium and Aluminium alloys Dissimilar Joining by Friction Stir Welding

Abstract Multi-material lightweight structures are gaining a great deal of attention in several industries, in particular where a trade-off between reduced weight, improved performances, and cost compression is required. Magnesium alloys, such as the zinc-rare earth elements ZE41A alloy, fulfill the first two requirements; however, they are susceptible to corrosion and relatively expensive. Lightweight structures hybridization, for instance combining Magnesium alloys and Aluminium alloys, is currently under consideration as a potential solution to this problem. Nevertheless, dissimilar joining of Magnesium and Aluminium alloys is challenging due to the significant differences in physical properties, as well as to the precipitation of brittle intermetallic compounds, such as Al 12 Mg 17 and Al 3 Mg 2 . In this study, the dissimilar joining of Magnesium and Aluminium alloys by friction stir welding process is discussed. In particular, 4 mm thick plates of ZE41A Mg alloy and AA2024-T3 Al alloy were welded in the butt joint configuration. The feasibility of the process was assessed by means of microstructure and mechanical analysis. The formation of brittle intermetallic compounds was investigated as well

Electrochemical investigation on localised corrosion under silica sand deposit layers of carbon steel within a bespoke test cell

The corrosion behaviour of deep pit-like features on carbon steel under silica sand deposits has been evaluated using a bespoke localised corrosion cell. Local pH and electrochemical measurements were performed, including impedance spectroscopy and galvanic coupling. The corrosion rate of X65 carbon steel at four different recession depths up to 9 mm was evaluated in the presence and absence of a ∼8 mm-thick silica dioxide deposit layer, in a carbon dioxide-saturated environment. The deposit reduced corrosion rates to approximately 1 mm·yr−1 and iron carbonate formed on the steel surface under the deposit due to an increase in local pH

Linear friction weld process monitoring of fixture cassette deformations using empirical mode decomposition

Due to its inherent advantages, linear friction welding is a solid-state joining process of increasing importance to the aerospace, automotive, medical and power generation equipment industries. Tangential oscillations and forge stroke during the burn-off phase of the joining process introduce essential dynamic forces, which can also be detrimental to the welding process. Since burn-off is a critical phase in the manufacturing stage, process monitoring is fundamental for quality and stability control purposes. This study aims to improve workholding stability through the analysis of fixture cassette deformations. Methods and procedures for process monitoring are developed and implemented in a fail-or-pass assessment system for fixture cassette deformations during the burn-off phase. Additionally, the de-noised signals are compared to results from previous production runs. The observed deformations as a consequence of the forces acting on the fixture cassette are measured directly during the welding process. Data on the linear friction-welding machine are acquired and de-noised using empirical mode decomposition, before the burn-off phase is extracted. This approach enables a direct, objective comparison of the signal features with trends from previous successful welds. The capacity of the whole process monitoring system is validated and demonstrated through the analysis of a large number of signals obtained from welding experiments

Evaluating localised under deposit corrosion and inhibition of carbon steel in CO2 saturated environments

When sand in present in low velocity energy transport pipework it tends to settle on internal areas interacting with the natural corrosion processes. In carbon dioxide (CO2)-saturated environments the presence of settled sand can severely impact corrosion rates. This type of corrosion is termed under deposit corrosion. In long-standing in-service pipelines, the natural corrosion processes can result in large areas of localised corrosion termed “pits”. Sand particles naturally gravitate to these areas manifesting pits under a deposit termed “under deposit localised corrosion”. Several problems exist surrounding the presence of under deposit localised corrosion, including an inability to effectively stifle corrosion in these environments using chemical corrosion inhibitors. A lack of understanding exists on the chemical properties within these environments and the mechanisms of inhibition in these environments which forms the basis of the work in this thesis. A three-step approach to determine the effectiveness of corrosion inhibitors on X65 carbon steel in under deposit localised corrosion is developed within this thesis. Stage 1 evaluates the effect of two corrosion inhibitors and their blend in reducing the corrosion rate of X65 carbon steel in CO2-saturated 20 g L-1 NaCl electrolyte at 50 °C, pH 4. The sulphur-based inhibitor produced an inhibitor efficiency (IE) of 94 %, whereas the imidazoline-based inhibitor was slightly less effective at 83 %. The blend showed synergistic capabilities with an IE of 99 %. Stage 2 evaluates the inhibitor transport properties of the inhibitors and their blend. A test cell was designed to direct the flow of inhibitor through a SiO2 deposit layer of 8 mm thickness (100 g dry deposit). The corrosion rate of X65 carbon steel was monitored. The sulphur-based inhibitor was somewhat effective with an IE of 47 %. The imidazoline and surprisingly the blend were ineffective in reaching the specimen in quantities sufficient to alter electrochemical behaviour. A bespoke under deposit localised corrosion test cell was used to evaluate the corrosion rate of X65 carbon steel at varying specimen recession (pits) in the presence and absence of a deposit. The corrosion rate reduced considerably with the presence of 100 g SiO2 deposit. Post-experimental analysis confirmed the precipitation of iron carbonate (FeCO3) under the deposit layer. Precipitation was related to an increase in near-surface pH measured using a thin shaft pH probe, at increased recession depth under deposit. Stage 3 evaluates inhibition in under deposit localised corrosion scenarios. The corrosion rate of specimens at recession depths of 0 mm and 9 mm under a thick SiO2 deposit layer was measured. The sulphur-based inhibitor was able to effectively reduce corrosion rates, however, IE reduced with recession depth. The imidazoline and the blend were ineffective in all under deposit scenarios. The galvanic coupling effect between an exposed and under deposit specimen was also evaluated and showed all inhibitors caused a drastic increase in corrosion rate with the introduction of inhibitor. In all cases, the under deposit specimen acted as the net cathode and the increased corrosion rate was sustained for the duration of the 20 h test. Overall, results showed the three-step approach could effectively be used to screen corrosion inhibitors for their performance in under deposit localised corrosion scenarios

Linear friction welding of aluminium to magnesium

Joining of an aluminium alloy to a magnesium alloy (AA 6082-T6 to AZ31) has been carried out by linear friction welding. The joining of this material combination is of particular significance for automotive components. Results show that welds with reasonable strength (comparable to the yield strength of the parent materials in O temper) can be produced. Weld microstructures were characterised by backscattered scanning electron microscopy, hardness testing and laboratory based X-ray diffraction. A particular emphasis was placed on determining the effects of welding parameters on the relative amounts of detrimental intermetallic phase at the weld line