Polyakov Loops and Magnetic Screening from Monopoles in SU(2) Lattice Gauge Theory

We present results from magnetic monopoles in $SU(2)$ lattice gauge theory at finite temperature. The lattices are $16^{3}\times N_{t}$, for $N_{t}=4,6,8,12$, at $\beta=2.5115$. Quantities discussed are: the spacial string tension, Polyakov loops, and the screening of timelike and spacelike magnetic currents.Comment: 5 pages, four Postscript figures, Late

Tribology matters

Tribology touches every aspect of our day to day existence and the wonder of this is that we are completely unaware how central it is to how we function. Take a snapshot of thebeginning of a normal working day for example. A typical morning start will involve brushing one's teeth with toothpaste containing mild abrasive (with a toothbrush with an optimized design for brushing efficiency), using a shampoo and conditioner which have been tested for frictional properties on a wide range of hair types, and for those who have the traditional morning fry up - lubricating the pan in advance with cooking oil to provide a boundary layer between the food and the pan and to reduce adhesion and heat transfer. It is clear that tribology plays a major role in our everyday lives. Whether starting out for work by foot, bicycle or car, friction will define whether our shoes or tyres can grip the road surface and whether the brake or clutch will do their job. If it is raining, the speed limit is modified in some countries, testifying to the influence of tribologists in decision making in the transport industries

The death of John Stuart Mill

This article surveys the fiercely contested posthumous assessments of John Stuart Mill in the newspaper and periodical press, in the months following his death in May 1873, and elicits the broader intellectual context. Judgements made in the immediate wake of Mill's death influence biographers and historians to this day and provide an illuminating aperture into the politics and shifting ideological forces of the period. The article considers how Mill's failure to control his posthumous reputation demonstrates both the inextricable intertwining of politics and character in the 1870s, and the difficulties his allies faced. In particular, it shows the sharp division between Mill's middle and working class admirers; the use of James Mill's name as a rebuke to his son; the redefinition of Malthusianism in the 1870s; and how publication of Mill's Autobiography damaged his reputation. Finally, the article considers the relative absence of both theological and Darwinian critiques of Mill

Tribo-corrosion maps for application in bio-tribology : some new approaches

Advances in the study of tribo-corrosion of materials in recent years have included the development of mechanistic maps, showing the transitions between the regimes as a function of the main process parameters. In such cases, maps have been constructed in both two and three dimensions. There are now a variety of modelling algorithms which may be used to map a range of performance indicators over a multi-parameter space. The interactions of tribo-corrosion in biological environments are becoming of increasing importance

There's something in the way you move : horse racing and skiing are two sports where a better understanding of friction could work

Have you ever had the experience of gliding effortlessly across a dance floor with a partner of rugby-player proportions, yet endured a swollen ankle minutes later from the quickstep of someone half the size? Why does one twin sister seem to be "hard" on shoes while the other can make a pair last twice as long? The explanation for counterintuitive phenomena like these lies in the study of friction and wear - a field known as tribology - and an increasingly rich source of tribological data come from the science of sport

Erosion-corrosion maps for carbon steel in crude oil/water slurries : impact angle and applied potential effects

In studies of erosion-corrosion, there have been few investigations into the effect of tribological issues, such as particle impact and impact angle, on erosion-corrosion of materials in oil field production. Despite this fact, erosion-corrosion in such environments is a major issue. In such conditions, it is important to define regimes where the effect of lubricating oil may modify the erosion properties of the materials. In this study, the combined effects of erosion and corrosion were investigated in three environments, crude oil (high API gravity 52), reservoir water, and 20% reservoir water with crude oil at a range of applied potentials. Erosion-corrosion maps were constructed, based on the results, showing the change in mechanisms and wastage rates as a function of impact angle and applied potential. Regimes of erosion-corrosion were described on such maps using such an approach. From this work, it can be seen that the corrosion contribution was increased with an increase in the percentage of reservoir water. In the crude oil environment, it was shown that the erosion contribution (Ke) was generally higher than that for corrosion suggesting that corrosion was reduced in crude oil. The results are interpreted in terms of the effect of the crude oil environment in modifying the impact properties of the particles therefore providing surprising resistance to particle impacts in nominally aggressive corrosion environments

A note on threshold velocity criteria for modelling the solid particle erosion of WC/Co MMCs

The threshold velocity for erosion of a ductile material is considered as the velocity required for initiation of plastic deformation in the substrate. For a brittle material, it defines the velocity required to nucleate a median crack in the elastic/plastic interface beneath the indentation. By invoking models for the solid particle erosion of ductile and brittle materials from the literature, together with a set of criteria based on threshold velocity calculations for erosion of the individual components, various predictions of erosion behaviour of WC/Co MMCs have been made. Qualitative agreement was found between the model predictions and various trends of the solid particle erosion behaviour of WC/Co cermets in the literature. The implications of the findings in addressing some of the puzzling trends of the solid particle erosion of MMCs in the literature, and how such insights may result in a reconsideration of some "classical" solid particle erosion relationships, are addressed in this paper

CFD modelling of erosion-corrosion of steel in aqueous environments : particle concentration effects on the regime boundaries

In this study, a new methodology is used to model the effects of particle concentration on the inner surfaces of a circular pipe 90º bend, assuming applied potential controlled aqueous slurry flow at room temperature. This enables the regimes of the component to be mapped according to the intensity of erosion and corrosion contributions. The results show that for a constant inlet particle concentration, it is shown how transitions between erosion-corrosion regimes are observed around the pipe. For increases in particle concentration, significant variation of the erosion-corrosion regimes are observed, with a reduction of the corrosion dominated regime. The results are interpreted in the terms of the changes in local erosion conditions along the component in the flowing environments. Typical results from the model are shown illustrating how this new mapping method can be used effectively to optimize process conditions and materials in such environments

Mapping erosion-corrosion of carbon steel in oil exploration conditions : some new approaches to characterizing mechanisms and synergies

Erosion by solid particles in oil/water slurries is a technologically important area. In such conditions, it is necessary to distinguish between the effects of the sand, aqueous environment, and the oil. Erosion-corrosion maps provide a means of identification between erosion-corrosion regimes as a function of erosion and corrosion parameters. However, there has been no work carried out to map the effects of parameters in oil/water slurries. This paper investigates the effect of erosion-corrosion on carbon steel in oil field production and maps the results. Distinctions between "synergistic" and "additive" erosion-corrosion behaviour are superimposed on the maps in the various environments