Grain selection and texture evolution in directionally solidified Al-Zn alloys

In a recent contribution, we have reported that dendrites in the aluminum-zinc binary system can change their growth direction continuously from {100} to {110} as the concentration of zinc CZn increases from 5 to 90 wt pct.[1] This was interpreted as an influence of the hcp Zn element on the low anisotropy of the solid-liquid interfacial energy of aluminum. Seaweed morphologies were even observed at the start and end of this so-called "dendrite orientation transition" (DOT), i.e., for CZn ≈ 30 and 55 wt pct. In the present work, we analyze how this DOT influences the selection of grains and the evolution of the texture in directionally solidified (DS) specimens. The solidification texturing of {hk0} dendritic specimens is shown to be similar to that occurring in normal {100} specimens. It is analyzed on a similar basis by considering a random orientation distribution of nuclei at the surface of the chill plate and a minimum undercooling criterion. This produces {hk0} textures with grains that look fairly "equiaxed" in transverse sections. For seaweed morphologies, which also exhibit an {hk0} texture parallel to the thermal gradient, the grain selection is slower and the grains appear more elongated in transverse sections. Their elongation occurs along a (001) plane, i.e., along a {120} direction for {210} seaweeds (CZn = 30 wt pct) and along a {110} direction for {110} seaweeds (CZn = 55 wt pct). The scanning electron microscopy (SEM) observations reveal that this elongation is accompanied by a microsegregation pattern that is mainly parallel to (001) planes. This indicates that seaweeds at the onset and end of the DOT grow with some type of layered structures, but their detailed growth and grain selection mechanisms are still unknown. © The Minerals, Metals & Materials Society and ASM International 2008

PHASE FIELD MODELING OF EQUILIBRIUM SHAPES AND GROWTH MORPHOLOGIES IN Al-Zn ALLOYS

The anisotropy of the solid-liquid interfacial energy, gamma(sl), plays a key role in the accurate prediction of growth morphologies in metallic alloys. This interfacial energy anisotropy can vary duo to alloy composition, especially when that of the pure solvent is weak. Recently Gonzales and Rappay, [1) showed the influence of an increasing zinc content on the growth direction of aluminum dendrites, which varied progressively from to as the zinc composition changed from 10 to 90 wt%. At the onset and end of this dendrito orientation transition (DOT), textured seaweeds were even observed. While this DOT could be simulated by phase field modeling with a change in the anisotropy of gamma(sl), seaweed could not be reproduced [2]. In order to explain this disagreement, it is necessary to have direct access to the anisotropy parameters. A combined numerical/experimental methodology to determine the needed experimental data is presented. It is based on inverse methods applied to 3D equilibrium shapes obtained by X-ray tomography. The gained anisotropy values are evaluated in a phase field code featuring a description of the interfacial energy anisotropy by a development up to the third order of the spherical harmonics for a cubic system. The hitter enables to model growth directions out of {110} planes, which was not possible with previous models

Asymmetry of price transmission within the French value chain of seafood products

A recent study in agricultural products has brought out evidence of asymmetrical transmission of price changes according to the sign (positive or negative) of past variation. Interestingly, asymmetry was more commonplace for products with a lower elasticity of supply due to the perishable nature of products. A similar study based on TAR and M-TAR cointegration models is carried out on the French markets for fish products. In particular, it investigates the relation between the characteristics of supply (farmed or wild-caught species) and the results regarding asymmetry of price transmission along the supply chain of fresh products. Like in previous studies, it is expected that farming, by increasing the security of supply, shows less asymmetry than wild caught products. Results bring no evidence of asymmetric price transmission in any value chain, whatever the origin of the supply, farmed or wild. It is nevertheless found differences in terms of speed of adjustment and size of margin that can be interpreted as a consequence of the uncertainty in the conditions of supply.Keywords: cointegration, asymmetric price transmission, TAR and M-TAR models, International Seafood Trade: Rules Based Reform, Fisheries Economics, fish value chain

Project overview and update on WEAVE: the next generation wide-field spectroscopy facility for the William Herschel Telescope

We present an overview of and status report on the WEAVE next-generation spectroscopy facility for the William Herschel Telescope (WHT). WEAVE principally targets optical ground-based follow up of upcoming ground-based (LOFAR) and space-based (Gaia) surveys. WEAVE is a multi-object and multi-IFU facility utilizing a new 2-degree prime focus field of view at the WHT, with a buffered pick-and-place positioner system hosting 1000 multi-object (MOS) fibres, 20 integral field units, or a single large IFU for each observation. The fibres are fed to a single spectrograph, with a pair of 8k(spectral) x 6k (spatial) pixel cameras, located within the WHT GHRIL enclosure on the telescope Nasmyth platform, supporting observations at R~5000 over the full 370-1000nm wavelength range in a single exposure, or a high resolution mode with limited coverage in each arm at R~20000. The project is now in the final design and early procurement phase, with commissioning at the telescope expected in 2017.Comment: 11 pages, 11 Figures, Summary of a presentation to Astronomical Telescopes and Instrumentation 201

ASS1 Overexpression:A Hallmark of Sonic Hedgehog Hepatocellular Adenomas; Recommendations for Clinical Practice

Until recently, 10% of hepatocellular adenomas (HCAs) remained unclassified (UHCA). Among the UHCAs, the sonic hedgehog HCA (shHCA) was defined by focal deletions that fuse the promoter of Inhibin beta E chain with GLI1. Prostaglandin D2 synthase was proposed as immunomarker. In parallel, our previous work using proteomic analysis showed that most UHCAs constitute a homogeneous subtype associated with overexpression of argininosuccinate synthase (ASS1). To clarify the use of ASS1 in the HCA classification and avoid misinterpretations of the immunohistochemical staining, the aims of this work were to study (1) the link between shHCA and ASS1 overexpression and (2) the clinical relevance of ASS1 overexpression for diagnosis. Molecular, proteomic, and immunohistochemical analyses were performed in UHCA cases of the Bordeaux series. The clinico-pathological features, including ASS1 immunohistochemical labeling, were analyzed on a large international series of 67 cases. ASS1 overexpression and the shHCA subgroup were superimposed in 15 cases studied by molecular analysis, establishing ASS1 overexpression as a hallmark of shHCA. Moreover, the ASS1 immunomarker was better than prostaglandin D2 synthase and only found positive in 7 of 22 shHCAs. Of the 67 UHCA cases, 58 (85.3%) overexpressed ASS1, four cases were ASS1 negative, and in five cases ASS1 was noncontributory. Proteomic analysis performed in the case of doubtful interpretation of ASS1 overexpression, especially on biopsies, can be a support to interpret such cases. ASS1 overexpression is a specific hallmark of shHCA known to be at high risk of bleeding. Therefore, ASS1 is an additional tool for HCA classification and clinical diagnosis

Using reduced rank regression methods to identify dietary patterns associated with obesity: a cross-country study among European and Australian adolescents

This study aims to examine repeatability of reduced rank regression (RRR) methods in calculating dietary patterns (DP) and cross-sectional associations with overweight (OW)/obesity across European and Australian samples of adolescents. Data from two cross-sectional surveys in Europe (2006/2007 Healthy Lifestyle in Europe by Nutrition in Adolescence study, including 1954 adolescents, 12-17 years) and Australia (2007 National Children's Nutrition and Physical Activity Survey, including 1498 adolescents, 12-16 years) were used. Dietary intake was measured using two non-consecutive, 24-h recalls. RRR was used to identify DP using dietary energy density, fibre density and percentage of energy intake from fat as the intermediate variables. Associations between DP scores and body mass/fat were examined using multivariable linear and logistic regression as appropriate, stratified by sex. The first DP extracted (labelled energy dense, high fat, low fibre') explained 47 and 31 % of the response variation in Australian and European adolescents, respectively. It was similar for European and Australian adolescents and characterised by higher consumption of biscuits/cakes, chocolate/confectionery, crisps/savoury snacks, sugar-sweetened beverages, and lower consumption of yogurt, high-fibre bread, vegetables and fresh fruit. DP scores were inversely associated with BMI z-scores in Australian adolescent boys and borderline inverse in European adolescent boys (so as with %BF). Similarly, a lower likelihood for OW in boys was observed with higher DP scores in both surveys. No such relationships were observed in adolescent girls. In conclusion, the DP identified in this cross-country study was comparable for European and Australian adolescents, demonstrating robustness of the RRR method in calculating DP among populations. However, longitudinal designs are more relevant when studying diet-obesity associations, to prevent reverse causality

Greenhouse gas emission scenarios in nine key non-G20 countries: An assessment of progress toward 2030 climate targets

This study compares greenhouse gas (GHG) emissions projections in 2030 under current policies and those under 2030 mitigation targets for nine key non-G20 countries, that collectively account for about 5 % of global total emissions today. These include the four largest non-G20 fossil CO2 emitting Parties to the UN climate convention pre- Paris Agreement (Iran, Kazakhstan, Thailand and Ukraine) and one of the largest land-use GHG emitters in the world (Democratic Republic of the Congo). Other countries assessed include major economies in their respective regions (Chile, Colombia, Morocco and the Philippines). In addition to economy-wide GHG emissions projections, we also assessed the projected GHG emissions peak year and the progression of per capita GHG emissions up to 2030. Our GHG emissions projections are also compared with previous studies. On economy-wide GHG emissions, Colombia, Iran, Morocco, and Ukraine were projected to likely meet or significantly overachieve their unconditional 2030 targets with existing policies, while DRC and Thailand would come very close to their targets. Kazakhstan and the Philippines would need to strengthen their action to meet their targets, while Chile recently raised its 2030 target ambition. Only Colombia and Ukraine are projected to have peaked their emissions by 2030. Per capita GHG emissions excluding land-use under current policies were projected to increase in all countries from 2010 levels by 8 % to over 40 % depending on the country. While the impact of the COVID-19 crisis on 2030 emissions is highly uncertain, our assessment on the target achievement would not change for most countries when the emission reductions estimated for 2020 in the literature were assumed to remain in 2030. The findings of this study highlight the importance of enhanced and frequent progress-tracking of climate action of major emitters outside G20, as is currently done for G20 members, to ensure that the global collective progress will become aligned with the pathways toward Paris climate goals

Greenhouse gas emission scenarios in nine key non-G20 countries: An assessment of progress toward 2030 climate targets

This study compares greenhouse gas (GHG) emissions projections in 2030 under current policies and those under 2030 mitigation targets for nine key non-G20 countries, that collectively account for about 5 % of global total emissions today. These include the four largest non-G20 fossil CO2 emitting Parties to the UN climate convention pre- Paris Agreement (Iran, Kazakhstan, Thailand and Ukraine) and one of the largest land-use GHG emitters in the world (Democratic Republic of the Congo). Other countries assessed include major economies in their respective regions (Chile, Colombia, Morocco and the Philippines). In addition to economy-wide GHG emissions projections, we also assessed the projected GHG emissions peak year and the progression of per capita GHG emissions up to 2030. Our GHG emissions projections are also compared with previous studies. On economy-wide GHG emissions, Colombia, Iran, Morocco, and Ukraine were projected to likely meet or significantly overachieve their unconditional 2030 targets with existing policies, while DRC and Thailand would come very close to their targets. Kazakhstan and the Philippines would need to strengthen their action to meet their targets, while Chile recently raised its 2030 target ambition. Only Colombia and Ukraine are projected to have peaked their emissions by 2030. Per capita GHG emissions excluding land-use under current policies were projected to increase in all countries from 2010 levels by 8 % to over 40 % depending on the country. While the impact of the COVID-19 crisis on 2030 emissions is highly uncertain, our assessment on the target achievement would not change for most countries when the emission reductions estimated for 2020 in the literature were assumed to remain in 2030. The findings of this study highlight the importance of enhanced and frequent progress-tracking of climate action of major emitters outside G20, as is currently done for G20 members, to ensure that the global collective progress will become aligned with the pathways toward Paris climate goals