The influence of Widmanstätten ferrite, martensite and grain boundary carbides on the strength and impact behaviour of high Al (0.2%) and Nb containing hot rolled steels

The influence of Al and Nb on the strength and impact behaviour of hot rolled 0.06%C, 1.4%Mn steels has been determined after hot rolling to 15 and 30 mm thick plate. When 0.16%Al was added to the plain C-Mn steel, the impact behaviour significantly improved even though Widmanstätten ferrite (WF) was present. This improvement was due to refinement of the grain boundary carbides and removing the N from solution as AlN. The hot rolled steels all contained WF but when Nb was added more WF formed as well as MA giving poor impact behaviour. Reducing the hardenability from that shown in previous work by decreasing C from 0.1 to 0.06%, Nb from 0.03 to 0.02%, and cooling rate from 33 to 17 K/min had no effect in improving the impact performance of hot rolled Nb steels. To ensure optimum properties not only is it necessary to reduce the hardenability, but WF formation must be discouraged by having a high Ar3. This can only be presently achieved by refining the austenite grain size via control rolling the Nb containing steels; the benefit of adding Al can then, readily be seen. Suggestions are made as to how this might be achieved for hot rolling

Ecojusticia, equidad y ética: retos para la orientación educativa y profesional

In social and environmental terms we live in precarious and uncertain times, where not only the sustainability of the planet rests in the balance, but also that of human existence. Many nation-states around the world talk of the importance of social cohesion, and are aware of the threat of environmental degradation, climate change, and ecological well-being. However, the dominating global policy discourse, particularly championed in the West, is located within a delimiting neo/liberal political framework. With a few noticeable exceptions, the influence of neo/liberal thinking continues to flourish in the contemporary career literature where there has been little deep critical engagement with the discourse of capitalist economics and how these impact human and environmental well-being. Often caught up in market-led discourses, and captured by the notion that ‘work sets you free’, educational and career guidance has been located within an uncritical economic frame. Its energies tend to be directed towards the preparation of individuals to make ‘good’ educational and occupational choices, underpinned by the need for ‘clients’ to acquire the skills and competencies demanded by employers (and the economy) (Bengtsson, 2011; Irving, 2018). The disjuncture between educational and career guidance and social and environmental justice (i.e. ecojustice) has rarely been breached. In this article, we seek to disrupt dominant discourses of the market that currently permeates thinking in education by identifying how an ecojustice perspective provides a forward looking and equitable foundation for educational and career guidance.En términos sociales y ambientales, vivimos en tiempos precarios e inciertos, donde no solo la sostenibilidad del planeta está en juego, sino también la de la existencia humana. Muchos estados-nación de todo el mundo hablan de la importancia de la cohesión social y son conscientes de la degradación ambiental, el cambio climático y la amenaza al bienestar ecológico y social. Sin embargo, el discurso dominante de la política global, particularmente defendido en Occidente, se sitúa dentro de un marco político neoliberal. Con algunas notables excepciones, la influencia del pensamiento neoliberal continúa siendo hegemónico en el campo de la educación y de la orientación profesional, donde en términos generales ha habido poco compromiso crítico profundo con el discurso de la economía capitalista y cómo este impacta sobre el bienestar humano y ambiental. A menudo atrapada en discursos dirigidos por el mercado y por la noción de que "el trabajo nos hace libres", la orientación educativa y profesional se ha ubicado dentro de un marco económico acrítico. Se tiende a preparar a los individuos para tomar "buenas" decisiones educativas y ocupacionales, respaldadas por la necesidad de que adquieran las habilidades y competencias exigidas por los empleadores (y la economía) (Bengtsson, 2011; Irving, 2018). La disyuntiva entre la orientación educativa y profesional y la justicia social y ambiental (la ecojusticia) rara vez se ha abordado. En este artículo cuestionamos los discursos dominantes del mercado que actualmente impregnan el pensamiento en educación, y proponemos la adopción de una perspectiva de ecojusticia que proporciona una guía para el futuro y contribuye a promover la equidad desde la orientación educativa y profesional

The implications of a changing climate on agricultural land classification in England and Wales

The agricultural land classification (ALC) of England and Wales is a formal method of assessing the quality of agricultural land and guiding future land use. It assesses several soil, site and climate criteria and classifies land according to whichever is the most limiting. A common approach is required for calculating the necessary agroclimatic parameters over time in order to determine the effects of changes in the climate on land grading. In the present paper, climatic parameters required by the ALC classification have been re-calculated from a range of primary climate data, available from the Meteorological Office's UKCP09 historical dataset, provided as 5 km rasters for every month from 1914 to 2000. Thirty-year averages of the various agroclimatic properties were created for 1921–50, 1931–60, 1941–70, 1951–80, 1961–90 and 1971–2000. Soil records from the National Soil Inventory on a 5 km grid across England and Wales were used to determine the required soil and site parameters for determining ALC grade. Over the 80-year period it was shown that the overall climate was coolest during 1951–80. However, the area of land estimated in retrospect as ‘best and most versatile (BMV) land’ (Grades 1, 2 and 3a) probably peaked in the 1951–80 period as the cooler climate resulted in fewer droughty soils, more than offsetting the land which was downgraded by the climate being too cold. Overall there has been little change in the proportions of ALC grades among the six periods once all 10 factors (climate, gradient, flooding, texture, depth, stoniness, chemical, soil wetness, droughtiness and erosion) are taken into account. This is because it is rare for changes in climate variables all to point in the same direction in terms of ALC. Thus, a reduction in rainfall could result in higher grades in wetter areas but lead to lower classification in drier areas

Habitability of known exoplanetary systems based on measured stellar properties

At present, because of observational selection effects, we know of no exoplanetary systems with any planetary masses close to that of the Earth. We have therefore used computer models to see whether such planets could be dynamically stable in the presence of the more massive planets known to be present, and in particular whether planets with roughly an Earth mass could remain confined to the classical habitable zone (HZ) for long enough for life to have emerged. Measured stellar properties have been used to determine for each system the present location of the HZ. We have also determined the critical distances from the orbit of each giant planet within which an Earth-mass planet would suffer large orbital changes. We then evaluated the present habitability of each and every exoplanetary system by examining the penetration of these critical distances into the HZ. The critical distances can be obtained by extensive computer modelling of an exoplanetary system. This is far too time consuming to apply to all of the 150 or so systems already known, and to keep up with the latest discoveries. Therefore, in earlier work we studied a few systems in great detail, and developed a speedier means of obtaining the critical distances. We summarize this comparatively quick method here. We can then evaluate comparatively quickly the present habitability of each exoplanetary system by examining the penetration of the critical distance(s) into the HZ. The results are encouraging for astrobiology.Comment: Accepted for publication by The Astrophysical Journal. A few revisions have been made following suggestions by the refere

Kingdom of trolls? Influence operations in the Saudi Twittersphere

Saudi Arabia has one of the highest rates of Twitter penetration in the world. Despite high levels of repression, the platform is frequently used to discuss political topics. Recent disclosures from Twitter have revealed state-backed attempts at distorting the online information environment through influence operations (IOs). A growing body of research has investigated online disinformation and foreign-sponsored IOs in the English-speaking world; but comparatively little is known about online disinformation in other contexts or about the domestic use of IOs. Using public releases of IO tweets, we investigate the extent of such activity in Saudi Arabia. Benchmarking these tweets to four samples of Saudi Twitter users, we find that engagement with IO accounts was lower than engagement with the average user, but equal to engagement with news accounts. Network analysis reveals that engagement with IO accounts was largely driven by a small number of influential accounts

Estimation of stratospheric input to the Arctic troposphere: 7Be and 10Be in aerosols at Alert, Canada

Concentrations of 7Be and 210Pb in 2 years of weekly high-volume aerosol samples collected at Alert, Northwest Territories, Canada, showed pronounced seasonal variations. We observed a broad winter peak in 210Pb concentration and a spring peak in 7Be. These peaks were similar in magnitude and duration to previously reported results for a number of stations in the Arctic Basin. Beryllium 10 concentrations (determined only during the first year of this study) were well correlated with those of 7Be; the atom ratio 10Be/7Be was nearly constant at 2.2 throughout the year. This relatively high value of 10Be/7Be indicates that the stratosphere must constitute an important source of both Be isotopes in the Arctic troposphere throughout the year. A simple mixing model based on the small seasonal variations of 10Be/7Be indicates an approximately twofold increase of stratospheric influence in the free troposphere in late summer. The spring maxima in concentrations of both Be isotopes at the surface apparently reflect vertical mixing in rather than stratospheric injections into the troposphere. We have merged the results of the Be-based mixing model with weekly O3 soundings to assess Arctic stratospheric impact on the surface O3 budget at Alert. The resulting estimates indicate that stratospheric inputs can account for a maximum of 10-15% of the 03 at the surface in spring and for less during the rest of the year. These estimates are most uncertain during the winter. The combination of Be isotopic measurements and O3 vertical profiles could allow quantification of the contributions of O3 from the Arctic stratosphere and lower latitude regions to the O3 budget in the Arctic troposphere. Although at present the lack of a quantitative understanding of the temporal variation of O3 lifetime in the Arctic troposphere precludes making definitive calculations, qualitative examples of the power of this approach are given

Guideline for UK midwives/health visitors to use with parents of infants at risk of developing childhood overweight/obesity

A guideline for members of the health visiting team to use with parents of infants at risk of overweight/obesity has been developed. The guideline contains recommendations about identification of infants at risk as well as a number of strategies that could be used for prevention of overweight/obesity. The guideline needs to be applied alongside health visitors’ professional judgement. It is not intended to replace normal UK clinical practice which is guided by the Healthy Child Programme and complements existing guidance such as the Framework for Action for tackling obesity