Weak lensing study of Abell 2029

Abell 2029 is one of the most studied clusters due to its proximity (z=0.07), its strong X-ray brightness and its giant cD galaxy which is one of the biggest stellar aggregates we know. We present here the first weak lensing mass reconstruction of this cluster made from a deep I-band image of 28.5'x28.5' centered on the cluster cD galaxy. This preliminary result allows us already to show the shape similarities between the cD galaxy and the cluster itself, suggesting that they form actually a single structure. We find a lower estimate of the total mass of 1.8 10^14 h^-1 solar masses within a radius of 0.3 h^-1 Mpc. We finally compute the mass-to-cD-light ratio and its evolution as a function of scale.Comment: 5 pages, to appear in the proceedings of "Matter and Energy in Clusters of Galaxies", ASP Conference Serie

Lorentzian Condition in Holographic Cosmology

We derive a sufficient set of conditions on the Euclidean boundary theory in dS/CFT for it to predict classical, Lorentzian bulk evolution at large spatial volumes. Our derivation makes use of a canonical transformation to express the bulk wave function at large volume in terms of the sources of the dual partition function. This enables a sharper formulation of dS/CFT. The conditions under which the boundary theory predicts classical bulk evolution are stronger than the criteria usually employed in quantum cosmology. We illustrate this in a homogeneous isotropic minisuperspace model of gravity coupled to a scalar field in which we identify the ensemble of classical histories explicitly.Comment: 34 pages, 6 figures, revtex

Squashed Holography with Scalar Condensates

We evaluate the partition function of the free and interacting O(N) vector model on a two-parameter family of squashed three spheres in the presence of a scalar deformation. We also find everywhere regular solutions of Einstein gravity coupled to a scalar field in AdS and in dS with the same double squashed boundary geometry. Remarkably, the thermodynamic properties of the AdS solutions qualitatively agree with the behavior predicted by the free O(N) model with a real mass deformation. The dS bulk solutions specify the semiclassical `no-boundary' measure over anisotropic deformations of inflationary, asymptotic de Sitter space. Through dS/CFT the partition function of the interacting O(N) model yields a holographic toy model of the no-boundary measure. We find this yields a qualitatively similar probability distribution which is normalizable and globally peaked at the round three sphere, with a low amplitude for strong anisotropies.Comment: 35 pages, version 2: presentation changed and comments adde

Characterization of sulfur distribution in Ni-based superalloy and thermal barrier coatings after high temperature oxidation: a SIMS analysis

Sulfur segregation was characterized by secondary ion mass spectrometry (SIMS) in uncoated single-crystal Ni-based AM1 superalloys with various S contents and on NiPtAl, NiAl and NiPt bondcoats of complete TBC systems. In spite of technical difficulties associated with diffuse sputtered interfaces, an original sample preparation technique and a careful choice of analysis conditions enabled a chemical characterization of S distribution below metal/oxide interfaces. An initial heterogeneous distribution of S in as-received high S (3.2 ppmw) AM1 was measured. After oxidation, a S depletion profile formed, with a slope that depended on the initial bulk S content. GDMS measurements enabled a quantitative distribution of S in oxidized low S (0.14 ppmw) AM1 to be constructed and discussed in relation to equilibrium surface segregation of S on Ni. The quantity of S integrated in the thermally grown oxide (TGO) was estimated and found to be very similar to that measured from depletion found in the metal. Localized S enrichments in Pt-containing coatings are related to a possible beneficial trapping mechanism of Pt on the adherence of oxide scales

Quantum Transitions Through Cosmological Singularities

In a quantum theory of cosmology spacetime behaves classically only in limited patches of the configuration space on which the wave function of the universe is defined. Quantum transitions can connect classical evolution in different patches. Working in the saddle point approximation and in minisuperspace we compute quantum transitions connecting inflationary histories across a de Sitter like throat or a singularity. This supplies probabilities for how an inflating universe, when evolved backwards, transitions and branches into an ensemble of histories on the opposite side of a quantum bounce. Generalising our analysis to scalar potentials with negative regions we identify saddle points describing a quantum transition between a classically contracting, crunching ekpyrotic phase and an inflationary universe.Comment: 32 pages, 27 figure

The design of a composite folding bike to improve the user experience of commuters

Over the last years, the popularity of folding bikes has been increasing as a result of the rise of multi-modal transport. They are used by commuters as a complement to public transport. Despite the increasing popularity, the current market offer of folding bikes still represents quite some restrictions and downsides which decrease their usability. This paper shows a user-centred process of designing and prototyping a composite folding bike with the aim of improving the user experience of folding bike using commuters. By improving the usability and ease of use of folding bikes, their full potential can be unlocked. The design process led to a disruptive folding bike design with front and rear single-sided offset wheel mounting. The concept excels in its intuitive and quick folding mechanism, superior riding performance and comfort, adjustability and overall ease of use. In addition to the design process and prototyping of the folding bike, this extended abstract elaborates on the performed user tests and its results. These tests range from the impact of offset wheels to the intuitiveness of the folding mechanism and were performed in order to prove different aspects of the design. This research shows how rethinking and redesigning a bike concept (product) from scratch, using a user-centred design process and taking into account the three aspects — business, technology and people — can lead to a disruptive design that improves usability and the overall user experience of the stakeholders

Applicability of trials in rheumatoid arthritis and osteoarthritis: A systematic review and meta-analysis of trial populations showing adequate proportion of women, but underrepresentation of elderly people

Objectives: To evaluate whether elderly people and women are adequately represented in randomized controlled trials (RCT) in rheumatoid arthritis (RA) and osteoarthritis (OA). Methods: Four systematic searches in MEDLINE yielded RCT in RA and OA on any intervention published in 2016 and 2017 and population-based studies (PBS) in RA and OA published between 2013 and 2017. Random effects meta-analyses estimated the pooled proportion of elderly people (defined as being ≥ 65 years old), the mean age, its standard deviation (SD), and the proportion of women stratified by disease (RA and OA) and study type (RCT and PBS). Stratified estimates were subsequently compared. Results: 265 RCT comprising 51,240 participants and 53 PBS comprising 523,630 participants were included. In both RA and OA, RCT included lower proportions of elderly people than PBS: RA –0.18 (95% confidence interval –0.22 to –0.13); OA –0.20 (–0.30 to –0.09); had lower mean ages: RA –5.2 years (–6.8 to –3.5); OA –4.7 years (–7.5 to –2.0); and smaller SD: RA –1.9 years (–2.6 to –1.3); OA –2.7 years (–4.2 to –1.2); (all comparisons: p ≤ 0.001). Proportions of women were comparable in RCT compared to PBS in both RA and OA. Conclusions: While women are adequately represented in RA and OA trials, the elderly are underrepresented, probably limiting applicability of current evidence to this growing subgroup. It is urgent to improve the inclusion of elderly people in clinical trials and study age as a determinant for outcome

Accurate Sharp Interface Scheme for Multimaterials

We present a method to capture the evolution of a contact discontinuity separating two different material. A locally non-conservative scheme allows an accurate and stable simulation while the interface is kept sharp. Numerical illustrations include problems involving fluid and elastic problems