Development of a novel metastable composite material

The development of a new family of mouldable metastable composite materials has been demonstrated. Their special quality is derived from the ability to maintain the matrix as a supercooled liquid or gel whose solidification can be triggered mechanically, as desired, by a user. This article describes some aspects of the development work. In particular, the following are explained: the choice of matrix material; the use of additives to enhance the properties of the matrix; and the selection of reinforcement fibre. As part of the work, some mechanical testing was performed on several variations of a matrix-fibre pair and, to demonstrate the potential of such materials, some comparisons were made with a possible competitor material, a glass-reinforced urethane. It was shown that the metastable material could be formulated to provide mechanical properties that would make it suitable for applications such as orthopaedic casting, splinting and body armour, and in items of sports equipment, these being areas where its mouldability could be particularly desirable

Sources of anthropogenic C-14 to the North Sea

The Sellafield nuclear fuel reprocessing plant on the northwest coast of England is the largest source of anthropogenic radiocarbon to the UK coastal environment. In a mid-1990s study of C-14 distribution around the UK coast, the pattern of dilution with increasing distance from Sellafield appeared to be perturbed by anomalously high C-14 activities in marine biota in the coastal environment of northeast England. This present study was undertaken during 1998 and 1999 to determine whether this C-14 enhancement was due to Sellafield or the nuclear power plants on the east coast. Seawater, seaweed (Fucus sp.), and mussel (Mytilus edulis) samples that were collected from the vicinity of the Torness and Hartlepool advanced gas-cooled reactor (AGR) nuclear power stations were all enhanced above the contemporary regional background activity derived from natural production and atmospheric nuclear weapons testing. We used previously published dilution factors and transfer times for Tc-99 between Sellafield and various points on the UK coast to determine likely Sellafield- derived C-14 contributions to the activities at the nuclear power plant sites. The results suggest that the activities observed at Torness, which are only marginally enhanced above the natural background activity, are possibly due to discharges from Sellafield; however, the significant C-14 enhancements at Hartlepool are not Sellafield-derived. Furthermore, since both reactors have the same fundamental design, the low activities at the Torness AGR imply that the activities at Hartlepool are not from the AGR, suggesting that there is an input of C-14 to the marine environment in the vicinity of Hartlepool which is probably non-nuclear-power related. However, there is no other authorized site in the area that could account for the observed C-14 enrichments; therefore, further research is required to ascertain the source of this C-14

On the Viability of Lattice Perturbation Theory

In this paper we show that the apparent failure of QCD lattice perturbation theory to account for Monte Carlo measurements of perturbative quantities results from choosing the bare lattice coupling constant as the expansion parameter. Using instead ``renormalized'' coupling constants defined in terms of physical quantities, like the heavy-quark potential, greatly enhances the predictive power of lattice perturbation theory. The quality of these predictions is further enhanced by a method for automatically determining the coupling-constant scale most appropriate to a particular quantity. We present a mean-field analysis that explains the large renormalizations relating lattice quantities, like the coupling constant, to their continuum analogues. This suggests a new prescription for designing lattice operators that are more continuum-like than conventional operators. Finally, we provide evidence that the scaling of physical quantities is asymptotic or perturbative already at $\beta$'s as low as 5.7, provided the evolution from scale to scale is analyzed using renormalized perturbation theory. This result indicates that reliable simulations of (quenched) QCD are possible at these same low $\beta$'s.Comment: 3

Eating the elephant whole or in slices: views of participants in a smoking cessation intervention trial on multiple behaviour changes as sequential or concurrent tasks

Background: This paper explores smoking cessation participants’ perceptions of attempting weight management alongside smoking cessation within the context of a health improvement intervention implemented in Glasgow, Scotland. <p/>Methods: One hundred and thirty-eight participants were recruited from smoking cessation classes in areas of multiple deprivation in Glasgow and randomised to intervention, receiving dietary advice, or to control groups. The primary outcome of the study was to determine the % change in body weight. Semi-structured interviews were conducted with a purposive sample of 15 intervention and 15 control participants at weeks 6 (during the intervention) and 24 (at the end of the intervention). The current paper, though predominantly qualitative, links perceptions of behaviour modification to % weight change and cessation rates at week 24 thereby enabling a better understanding of the mediators influencing multiple behaviour change. <p/>Results: Our findings suggest that participants who perceive separate behaviour changes as part of a broader approach to a healthier lifestyle, and hence attempt behaviour changes concurrently, may be at comparative advantage in positively achieving dual outcomes. <p/>Conclusions: These findings highlight the need to assess participants’ preference for attempting multiple behaviour changes sequentially or simultaneously in addition to assessing their readiness to change. Further testing of this hypothesis is warranted

Sellafield-derived anthropogenic C-14 in the marine intertidal environment of the NE Irish Sea

The intertidal biota from Parton beach, close to the Sellafield nuclear fuel reprocessing plant, were all found to be enriched in radiocarbon relative to ambient background. The degree of enrichment appears to reflect the positions of the biota in the food chain once the dilution in seaweed from atmospheric uptake is taken into account. Close to the low-water mark, the order was mussels gt limpets gt anemones congruent to winkles gt seaweed. The same order was observed close to the high-water mark, except that anemones were absent from this area. The activities in the biogeochemical fractions of the water column reflect the fact that discharges are primarily in the form of dissolved inorganic carbon (DIC), which is subsequently transferred to the particulate organic carbon (POC) and, to a lesser extent, the dissolved organic carbon (DOC), and finally, the particulate inorganic carbon (PIC). Analysis of intertidal sediment suggests that there is likely to be a gradual increase in the specific activity of C-14 in the inorganic component of this material as Sellafield contaminated organisms die and their shells are ground down by natural processes