Evolution of precipitates, in particular cruciform and cuboid particles, during simulated direct charging of thin slab cast vanadium microalloyed steels

A study has been undertaken of four vanadium based steels which have been processed by a simulated direct charging route using processing parameters typical of thin slab casting, where the cast product has a thickness of 50 to 80mm ( in this study 50 mm) and is fed directly to a furnace to equalise the microstructure prior to rolling. In the direct charging process, cooling rates are faster, equalisation times shorter and the amount of deformation introduced during rolling less than in conventional practice. Samples in this study were quenched after casting, after equalisation, after 4th rolling pass and after coiling, to follow the evolution of microstructure. The mechanical and toughness properties and the microstructural features might be expected to differ from equivalent steels, which have undergone conventional processing. The four low carbon steels (~0.06wt%) which were studied contained 0.1wt%V (V-N), 0.1wt%V and 0.010wt%Ti (V-Ti), 0.1wt%V and 0.03wt%Nb (V-Nb), and 0.1wt%V, 0.03wt%Nb and 0.007wt%Ti (V-Nb-Ti). Steels V-N and V-Ti contained around 0.02wt% N, while the other two contained about 0.01wt%N. The as-cast steels were heated at three equalising temperatures of 1050C, 1100C or 1200C and held for 30-60 minutes prior to rolling. Optical microscopy and analytical electron microscopy, including parallel electron energy loss spectroscopy (PEELS), were used to characterise the precipitates. In the as-cast condition, dendrites and plates were found. Cuboid particles were seen at this stage in Steel V-Ti, but they appeared only in the other steels after equalization. In addition, in the final product of all the steels, fine particles were seen, but it was only in the two titanium steels that cruciform precipitates were present. PEELS analysis showed that the dendrites, plates, cuboids, cruciforms and fine precipitates were essentially nitrides. The two Ti steels had better toughness than the other steels but inferior lower yield stress values. This was thought to be, in part, due to the formation of cruciform precipitates in austenite, thereby removing nitrogen and the microalloying elements which would have been expected to precipitate in ferrite as dispersion hardening particles

Using qualitative research to overcome the shortcomings of systematic reviews when designing of a self-management intervention for advanced cancer pain

Objectives: To identify the key components for a self-management intervention for advanced cancer pain using evidence drawn from systematic reviews of complex interventions and syntheses of qualitative research. Methods: Evidence from up-to-date systematic reviews was prioritised. Searches were initially undertaken to identify systematic reviews of effectiveness in Cinahl, Medline, Embase, PsycInfo and the Cochrane Database of Systematic Reviews from 2009-June 2014, using validated search terms. Subsequent searches to identify qualitative systematic reviews were undertaken in Cinahl, Medline, Embase, and PsycInfo from 2009- January 2015. The results of the two sets of reviews were integrated using methods based on constant comparative techniques. Results: Four systematic reviews examining interventions for the self-management of advanced cancer pain were identified. Whilst each review recommended some attributes of a pain management intervention, it was not possible to determine essential key components. Subsequent searches for qualitative evidence syntheses identified three reviews. These were integrated with the effectiveness reviews. The integration identified key components for a self-management intervention including: individualised approaches to care; the importance of addressing patients’ knowledge, skills and attitudes towards pain management; and the significance of team approaches and inter-disciplinary working in the management of pain. Conclusion: Implementing the findings from systematic reviews of complex interventions is often hindered by a lack of understanding of important contextual components of care, often provided by qualitative research. Using both types of data to provide answers for practice demonstrates the benefits of incorporating qualitative research in reviews of complex interventions by ensuring the strengths of qualitative and quantitative research are combined and that their respective weaknesses are overcome

Understanding the disorder of the DNA base cytosine on the Au(111) surface

Using ultrahigh vacuum scanning tunneling microscopy (STM) and ab initio density functional theory, we have investigated in detail structures formed by cytosine on the Au(111) surface in clean ultrahigh vacuum conditions. In spite of the fact that the ground state of this DNA base on the surface is shown to be an ordered arrangement of cytosine one-dimensional branches (filaments), this structure has never been observed in our STM experiments. Instead, disordered structures are observed, which can be explained by only a few elementary structural motifs: filaments, five- and sixfold rings, which randomly interconnect with each other forming bent chains, T junctions, and nanocages. The latter may have trapped smaller structures inside. The formation of such an unusual assembly is explained by simple kinetic arguments as a liquid-glass transition. © 2008 American Institute of Physics

Archaeology of the continental shelf : Marine resources, submerged landscapes and underwater archaeology

We provide a critical review of the evidence for the long-term use of marine resources and coastal environments in human evolution and later development. We emphasise the importance of the coastal archaeological record in understanding patterns of human settlement and dispersal and draw attention to the large potential biases introduced by the destructive or obscuring effects of Pleistocene sea-level change. We note that lowered sea levels have been the norm for most of the Pleistocene and that periods of high sea level have been too short-lived to provide other than a fragmentary coastal record and one that is beset with ambiguities and uncertainties. We examine the geological processes of coastal uplift and underwater preservation that may help to mitigate these biases. Coastlines elevated by isostatic and tectonic processes, or with very steep offshore drop-offs at plate boundaries, are important in providing a potential window into coastal landscapes and archaeology formed during periods of lowered sea level. However, we conclude that the opportunities afforded by these geological factors are too limited to obviate the need for underwater exploration. We review the evidence now available from Submerged landscapes across the Africa-Eurasia interface from the Atlantic coastlines of Northwest Europe to the southern Red Sea. We show that geomorphological conditions for the preservation of archaeological and palaeoenvironmental data are commonly present, that much material has already been discovered, and that new techniques, technologies and projects are providing the momentum for a rapidly expanding field of investigation. The results do not simply add to what we already know from sites on land, but are likely to produce qualitatively different evidence for coastal adaptations and landscapes that have no analogue on present-day coastlines. We note the strong probability that many coastal landscapes exposed at lowered sea level provided relatively fertile and productive refugia for plants, land mammals and humans at a time when increased aridity would have reduced or deterred hinterland occupation. We conclude that underwater investigation is essential if hypotheses of early human adaptation and dispersal are to be fully tested. (c) 2008 Elsevier Ltd. All rights reserved

Radiocarbon Chronologies and Extinction Dynamics of the Late Quaternary Mammalian Megafauna of the Taimyr Peninsula, Russian Federation

This paper presents 75 new radiocarbon dates based on late Quaternary mammal remains recovered from eastern Taimyr Peninsula and adjacent parts of the northern Siberian lowlands, Russian Federation, including specimens of woolly mammoth (Mammuthus primigenius), steppe bison (Bison priscus), muskox (Ovibos moschatus), moose (Alces alces), reindeer (Rangifer tarandus), horse (Equus caballus) and wolf (Canis lupus). New evidence permits reanalysis of megafaunal extinction dynamics in the Asian high Arctic periphery. Increasingly, radiometric records of individual species show evidence of a gap at or near the Pleistocene/Holocene boundary (PHB). In the past, the PHB gap was regarded as significant only when actually terminal, i.e., when it marked the apparent ‘‘last’’ occurrence of a species (e.g., current ‘‘last’’ occurrence date for woolly mammoth in mainland Eurasia is 9600 yr BP). However, for high Arctic populations of horses and muskoxen the gap marks an interruption rather than extinction, because their radiocarbon records resume, nearly simultaneously, much later in the Holocene. Taphonomic effects, ΔC14 flux, and biased sampling are unlikely explanations for these hiatuses. A possible explanation is that the gap is the signature of an event, of unknown nature, that prompted the nearly simultaneous crash of many megafaunal populations in the high Arctic and possibly elsewhere in Eurasia.

Udfordringer og dilemmaer i det offentlige-private samspil på beskæftigelsesområdet: markedsgørelse i flere versioner

Denne artikel rejser spørgsmålet om, hvordan det offentlige-private samspil på beskæftigelsesområdet har udviklet sig siden 2003, herunder hvilke udfordringer og dilemmaer der har været forbundet med disse udviklingstræk. Tilbage i 2003 blev store dele af beskæftigelsesindsatsen udliciteret til ikke-offentlige leverandører, hvormed der blev etableret et marked for andre (ikke-offentlige) aktører. Omfattende udbudsprocesser blev taget i brug, og de politiske forventninger var store. Ca. 12 år senere er markedet for private beskæftigelsesindsatser indskrænket væsentligt, og det offentlige-private samspil på beskæftigelsesområdet har bevæget sig i retning af en langt mere samarbejdsbaseret og lokal tilgang. Artiklen giver et indblik i, hvordan disse ændringer ikke blot har haft styringsmæssige konsekvenser men også indholdsmæssige, samt vanskelighederne ved at etablere et velfungerende marked på beskæftigelsesområdet, der lever op til de politiske hensigter