The fusion approach – applications for understanding local government and European integration

The article explores the theoretical capabilities of the fusion approach as a conceptual ‘kit’ to explain the ‘bigger picture’ of European integration from a local government perspective. Fusion addresses the rationales and methods facilitating the transfer of policy-making competences to the European level. It understands European integration as a merging of public resources and policy instruments from multiple levels of government, whereby accountability and responsibilities for policy outcomes become blurred. The article argues that the fusion approach is useful to explain the systemic linkages between macro-trajectories and the corresponding change at the local level; the fusion dynamics of the local and European levels in a common policy-cycle; and the attitudes of local actors towards the EU. Although the article concludes that local government is rather modestly ‘fused’ into the EU, fusion approaches allow examining the extent to which the local level has become integrated into the European governance system

Strength-ductility behaviour of Al-Si-Cu-Mg casting alloys in T6 temper

A comparative study of the mechanical properties of 20 experimental alloys has been carried out. The effect of different contents of Si, Cu, Mg, Fe and Mn, as well as solidification rate, has been assessed using a strength-ductility chart and a quality index-strength chart developed for the alloys. The charts show that the strength generally increases and the ductility decreases with an increasing content of Cu and Mg. Increased Fe (at Fe/Mn ratio 0.5) dramatically lowers the ductility and strength of low Si alloys. Increased Si content generally increases the strength and the ductility. The increase in ductility with increased Si is particularly significant when the Fe content is high. The charts are used to show that the cracking of second phase particles imposes a limit to the maximum achievable strength by limiting the ductility of strong alloys. The (Cu + Mg) content (at.%), which determines the precipitation strengthening and the volume fraction of Cu-rich and Mg-rich intermetallics, can be used to select the alloys for given strength and ductility, provided the Fe content stays below the Si-dependent critical level for the formation of pre-eutectic alpha-phase particles or beta-phase plates

Controlling the microstructure of Hastelloy-X components manufactured by selective laser melting

AbstractSelective Laser Melting (SLM) is steadily gaining acceptance across the manufacturing industry. Techniques for manufacturing components with complex geometries layer by layer have proven to be very effective in accelerating product development and hence reducing time to market. To build components by SLM from a nickel based super-alloy requires an understanding of process parameters and how they influence the microstructure, the degree of porosity and the properties. In this work, it was found that the as-fabricated density of parts manufactured from Hastelloy-X by SLM could be increased from 77 to 99% by decreasing the laser scan speed, and that the degree of cracking can be reduced by decreasing the amount of minor alloying additions such as Mn and Si

Screw-Related Complications After Instrumentation of the Osteoporotic Spine: A Systematic Literature Review With Meta-Analysis

Contains fulltext : 220967.pdf (publisher's version ) (Open Access)STUDY DESIGN: Systematic literature review with meta-analysis. OBJECTIVE: Osteoporosis is common in elderly patients, who frequently suffer from spinal fractures or degenerative diseases and often require surgical treatment with spinal instrumentation. Diminished bone quality impairs primary screw purchase, which may lead to loosening and its sequelae, in the worst case, revision surgery. Information about the incidence of spinal instrumentation-related complications in osteoporotic patients is currently limited to individual reports. We conducted a systematic literature review with the aim of quantifying the incidence of screw loosening in osteoporotic spines. METHODS: Publications on spinal instrumentation of osteoporotic patients reporting screw-related complications were identified in 3 databases. Data on screw loosening and other local complications was collected. Pooled risks of experiencing such complications were estimated with random effects models. Risk of bias in the individual studies was assessed with an adapted McHarm Scale. RESULTS: From 1831 initial matches, 32 were eligible and 19 reported screw loosening rates. Studies were heterogeneous concerning procedures performed and risk of bias. Screw loosening incidences were variable with a pooled risk of 22.5% (95% CI 10.8%-36.6%, 95% prediction interval [PI] 0%-81.2%) in reports on nonaugmented screws and 2.2% (95% CI 0.0%-7.2%, 95% PI 0%-25.1%) in reports on augmented screws. CONCLUSIONS: The findings of this meta-analysis suggest that screw loosening incidences may be considerably higher in osteoporotic spines than with normal bone mineral density. Screw augmentation may reduce loosening rates; however, this requires confirmation through clinical studies. Standardized reporting of prespecified complications should be enforced by publishers

Cyprus and the onset of Europeanization: strategic usage, structural transformation and institutional adaptation

This article analyzes the EU's impact on Cyprus during its 'pre-accession' phase. The processes of Europeanization are considered in terms of the structural transformation of state-economy relations (in which 'empowerment' is diffuse and differentiated among domestic actors); and the adaptation of the state administration (to the demands of coordination; readjustment of competencies). Across a range of domestic reforms, EU pressure has been crucial to its pace, if not also its content. With the exception of the events of 1974, the stimulus from the EU represents the most far-reaching transformation of Cypriot society in four decades of independence. Europeanization also plays a major role in the discourse of key actors on foreign policy (where the EU is seen as a vital foreign policy lever). Yet the high expectations of the EU to 'unblock' relations with Turkey poses important strategic risks for the EU should it fail to deliver

Out of this World Design: Bridging the Gap between Space Systems Engineering and Participatory Design Practices

Ongoing democratization of access to space in combination with the prospect of long-duration missions off-planet are setting the stage for a new era in human spaceflight. An era characterized by a growing spectrum of people with diverse professional and demographic backgrounds living and working in space. The development of human spaceflight systems has historically been intertwined with prototype studies in analogue environments that approximate some of the extreme conditions associated with space operations. Examples include hypogravity reenacted during parabolic flight campaigns or challenging lighting conditions assessed during experimental deployments in underground caves. The high cost and logistical complexity of such approaches pose a significant barrier to relevant design activities, typically leading to a low frequency of studies, a relatively small number of participants and slow feedback loops, all antithetical to modern participatory design practices. Whilst successful in underpinning the highly specialized and engineering-driven space programs of the past century, it is increasingly apparent that these traditional approaches to space systems engineering are poorly equipped to accommodate the forthcoming end-user diversification and normalization of space travel. To explore an alternative approach, our team is in the process of developing a testbed facility enhanced through the use of mixed reality technologies. By leveraging physical mockups, gravity-offload systems and digital set extensions, we demonstrate a comparatively cost-effective and accessible way of interactively simulating key challenges associated with space operations. With that, we seek to lower the threshold for participation of relevant stakeholders in design and evaluations of pertinent space solutions. We conclude by reflecting on the viability and potential importance of participatory design and rapid prototyping methods in shaping the future of humanity’s endeavours in space

Migration of Jupiter-mass planets in low-viscosity discs

International audienceContext. Type-II migration of giant planets has a speed proportional to the disc’s viscosity for values of the α viscosity parameter larger than 10−4. Previous studies based on two-dimensional simulations, have shown that, at even lower viscosities, migration can be very chaotic and is often characterised by phases of fast migration. The reason is that vortices appear in low-viscosity discs due to the Rossby-wave instability at the edges of the gap opened by the planet. Migration is then determined by vortex-planet interactions.Aims. Our goal is to study giant planet migration in low-viscosity discs with 3D simulations. In 3D, vortices are more complex than the simple vertical extension of their 2D counterparts; their impact on planet migration is therefore not obvious.Methods. We performed numerical simulations using two grid-based codes: FARGOCA for three-dimensional simulations and FARGO-ADSG for the two dimensional case. Two-dimensional simulations were used mainly for preliminary tests to check the impact of self-gravity on vortex formation and on vortex-disc dynamics. After selecting disc masses for which self-gravity is not important at the planet location, three-dimensional simulations without self-gravity can be safely used. We have considered an adiabatic equation of state with exponential damping of temperature perturbations in order to avoid the development of the vertical shear instability. In our nominal simulation, we set α = 0 so that only numerical viscosity is present. We then performed simulations with non-zero α values to assess the threshold of prescribed viscosity below which the new migration processes appear.Results. We show that for α ≲ 10−5 two migration modes are possible, which differ from classical Type-II migration in the sense that they are not proportional to the disc’s viscosity. The first occurs when the gap opened by the planet is not very deep. This occurs in 3D simulations and/or when a big vortex forms at the outer edge of the planetary gap, diffusing material into the gap. The de-saturation of co-orbital and co-rotation resonances keeps the planet’s eccentricity low. Inward planet migration then occurs as long as the disc can refill the gap left behind by the migrating planet, either due to diffusion caused by the presence of the vortex or to the inward migration of the vortex itself due to its interaction with the disc. We call this type of migration ‘vortex-driven migration’, which differs from ‘vortex-induced’ migration described in Lin & Papaloizou (2010, MNRAS, 405, 1473, and 2011a, MNRAS, 415, 1445). This migration is very slow and cannot continue indefinitely because eventually the vortex dissolves. The second migration mode occurs when the gap is deep so that the planet’s eccentricity grows to a value e ~ 0.2 due to inefficient eccentricity damping by co-rotation resonances. Once the planet is on an eccentric orbit, gas can pass through the gap and planet migration unlocks from the disc’s viscous evolution. This second, faster migration mode appears to be typical of two-dimensional models in discs with slower damping of temperature perturbations.Conclusions. Vortex-driven migration in low-viscosity discs can be very slow and eventually reverses and stops, offering an interesting mechanism to explain the existence of the cold-Jupiter population, even if these planets originally started growing at the disc’s snowline