Majority and minority influence: Source-position imbalance as a determinant of message scrutiny.

Two experiments addressed the issue of whether endorsement of a position by a numerical majority or a minority leads to greater scrutiny of the information presented in a persuasive message. In Exp 1, a counterattitudinal position was endorsed by a majority or a minority and was supported by strong or weak arguments. Argument quality had a larger impact on attitudes with majority than with minority endorsement. In Exp 2, a proattitudinal or a counterattitudinal message was endorsed by a majority or a minority and was supported by strong or weak arguments. When the source and message position were unexpected (i.e., majority-counter and minority-pro messages), argument quality had a larger impact on attitudes than when the source and message position were expected (i.e., majority-pro and minority-counter messages). Thus, either majority or minority endorsement can enhance message scrutiny if the source-position pairing is surprising. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Wear Mechanisms of Chromia Refractories in Slagging Gasifiers

The hot-face refractory lining is a key component of gasification systems. The refractory liner protects the gasification system from the high-temperature corrosive gaseous and from the molten slag environment associated with the conversion of carbon feedstocks. This paper will discuss the effect of gasifier operating conditions and carbon feedstock slag/ash chemistry on the refractory service life. Particular attention is focused on the wear mechanism of chromia refractories, determined through postmortem analysis of spent refractory bricks from service in gasifiers. Also presented is the behavior of a phosphate-containing chromia refractory with improved resistance to structural spalling.     

Evolution-in-materio: solving computational problems using carbon nanotube–polymer composites

Evolution-in-materio uses evolutionary algorithms to exploit properties of materials to solve computational problems without requiring a detailed understanding of such properties. We show that using a purpose-built hardware platform called Mecobo, it is possible to solve computational problems by evolving voltages and signals applied to an electrode array covered with a carbon nanotube–polymer composite. We demonstrate for the first time that this methodology can be applied to function optimization and also to the tone discriminator problem (TDP). For function optimization, we evaluate the approach on a suite of optimization benchmarks and obtain results that in some cases come very close to the global optimum or are comparable with those obtained using well-known software-based evolutionary approach. We also obtain good results in comparison with prior work on the tone discriminator problem. In the case of the TDP we also investigated the relative merits of different mixtures of materials and organizations of electrode array.     

A supply network-modelling system for a small- to medium-sized manufacturing company

During the late 1990s and early 2000s, the profile of global manufacturing has experienced many changes. There is anecdotal evidence that many western manufacturing companies have chosen to expand their manufacturing base across geographical boundaries. The common reasons sited for these ventures are to exploit less expensive labour markets, to establish a presence in expanding markets and in response to the threat of new competition. Whilst a global manufacturing base can prove to have many cost and sales benefits, there are also many disadvantages. Logistics operations can often increase in complexity leading to higher reliance on planning and effective interpretation of demand data. In response, systems modelling has remerged as a fertile research area after many years. Many modelling and simulation techniques have been developed, but these have had very limited practical success. The authors have identified that majority of these simulation techniques rely upon a detailed market structure being known, when this is rarely the case. This paper describes the outcome of a research project to develop of a pragmatic set of tools to gather, assess and verify supply chain structure data. A hybrid collection of technologies are utilised to assist these operations and to build a dynamic supply network model.     

The gradual threshold model of ambivalence: relating the positive and negative bases of attitudes to subjective ambivalence

Eighty subjects viewed and visually imagined upright or rotated alphanumeric characters and later judged whether test characters were previously seen or imagined (reality monitoring). Identification and test characters were presented verbally or visually. When characters were identified and tested verbally, source confusions (misjudging a seen character as "imagined" and vice-versa) were infrequent and were comparable for rotated and upright characters. When characters were identified and tested visually, source confusions were more frequent and were influenced by character rotation. Memories for imagined characters were especially susceptible to source confusion. Also source confusions for seen characters increased when characters were rotated. These results are consistent with the proposal that increasing sensory similarity between perceived and imagined items increases source confusion and that perceived rotation generates cognitive operations similar to those generated when the subject imagines a character rotated.     

A single chip multi-channel surface plasmon resonance imaging system

A single chip, multi-channel surface plasmon resonance (SPR) imaging system has been developed. The equipment has no moving parts and uses a single sensor chip on which multiple channels can be incorporated. A light emitting diode is used as a photon source while a CCD camera forms the detector. The optical configuration has been designed to achieve a uniform illumination of the sample over a fixed area with a range of incident angles. A calibration test using sucrose solutions shows that the sensitivity of the equipment is 4.3×10⁻⁴ refractive index units per pixel line-pair. The use of the system for simultaneous interrogation of different polyelectrolyte thin films, formed by the electrostatic layer-by-layer deposition method, is demonstrated. A reversible pH-dependent response for these organic layers is also reported.     

Environmental effects on the electrical behavior of pentacene thin-film transistors with a poly(methyl methacrylate) gate insulator

The electrical properties of top-contact pentacene thin-film transistors (TFTs) with a poly(methyl methacrylate) (PMMA) gate dielectric were analyzed in air and vacuum environments. Compared to the vacuum case, the pentacene TFT in air exhibited lower drain currents and more pronounced shifts in the threshold voltage upon reversal of the gate voltage sweep direction, together with a decrease in the field-effect mobility. These characteristic variations were explained in terms of two distinctive actions of polar H₂O molecules in pentacene TFT. H₂O molecules were suggested to diffuse under the source and drain contacts and interrupt the charge injection into the pentacene film, whereas those that permeate at the pentacene/PMMA interface retard hole depletion in and around the TFT channel. The diffusion process was much slower than the permeation process. The degraded TFT characteristics in air could be recovered mostly by storing the device under vacuum, which suggests that the air instability of TFTs is due mainly to the physical adsorption of H₂O molecules within the pentacene film.     

Processing effects in production of composite prepreg by hot melt impregnation

The hot melt impregnation process for producing composite prepreg has been studied. The role of the exit die is highlighted by operating without impregnation bars. Experimental results show that when a fiber two is pulled through a resin bath and then through a wedge shaped die, the total resin mass fraction and the extent of resin impregnation in the two increase with the processing viscosity. The penetration of resin into a fiber bundle is greater when the resin viscosity is higher. This trend is unchanged over a range of two speeds up to the breaking point. A theoretical model is developed to describe the effect of processing conditions and die geometry on the degree of impregnation. Calculations with this model indicate that for a given die geometry, the degree of impregnation increases from 58% to 90% as the ratio of the clearance between the two and the die wall, to the total die gap is decreased from 0.15 to 0.05. Physical arguments elated to the effective viscosity of the prepreg show that the clearance ratio is independent of the two speed, but decreases as the ratio of the effective shear viscosity of the prepareg to the resin viscosity increases. This provides a connection between the experimental results obtained with varying resin viscosity and the computational results obtained with varying clearance values at the die inlet.