Studying Policy Design Quality in Comparative Perspective

This article is a first attempt to systematically examine policy design and its influence on policyeffectiveness in a comparative perspective. We begin by providing a novel concept and measure ofpolicy design. Our Average Instrument Diversity (AID) index captures whether governments tendto reuse the same policy instruments and instrument combinations or produce policy solutions that arecarefully tailored to the policy problem at hand. Second, we demonstrate that our AID index is a valid andreliable measure of policy design quality with a strong explanatory power for the outcome variables tested.Analyzing the composition of environmental policy portfolios in 21OECDcountries, we show that higherlevels of AID are positively associated with a country’s policy effectiveness in environmental matters.Based on this finding, we analyze, in a third step, the factors that lead countries to adopt more or lessdiverse policy portfolios. We find that the policy design quality is significantly improved when policymakers are not bound b

Studying Policy Design Quality in Comparative Perspective

This article is a first attempt to systematically examine policy design and its influence on policyeffectiveness in a comparative perspective. We begin by providing a novel concept and measure ofpolicy design. Our Average Instrument Diversity (AID) index captures whether governments tendto reuse the same policy instruments and instrument combinations or produce policy solutions that arecarefully tailored to the policy problem at hand. Second, we demonstrate that our AID index is a valid andreliable measure of policy design quality with a strong explanatory power for the outcome variables tested.Analyzing the composition of environmental policy portfolios in 21OECDcountries, we show that higherlevels of AID are positively associated with a country’s policy effectiveness in environmental matters.Based on this finding, we analyze, in a third step, the factors that lead countries to adopt more or lessdiverse policy portfolios. We find that the policy design quality is significantly improved when policymakers are not bound b

Comparison of 2D and 3D simulations of solidification of binary and ternary Al-based alloys under RMF

Two-dimensional and three-dimensional numerical simulations of solidification of Al-7wt%Si and Al-7wt%Si-1wt%Fe under RMF stirring were performed and compared with the corresponding experimental data. It is demonstrated that 2D simulations provided segregation pattern similar to experimental data. Yet, the segregation patterns at the end of simulations performed in 2D are slightly different compared to the segregation map obtained in 3D simulations

Modelling of Al-7wt%Si-1wt%Fe ternary alloy: application to space experiments with a rotating magnetic field

Recently several experiments on directional solidification of Al-6.5wt.Si-0.93wt.%Fe (AlSi7Fe1) alloy were performed under terrestrial conditions and onboard the International Space Station (ISS) in the Materials Science Lab (MSL) with use of electromagnetic stirring and without it. Analysis of the samples showed that stirring with a rotating magnetic field lead to the accumulation of iron-rich intermetallics in the center of the sample and influenced the primary dendrite spacing while the secondary dendrite arm spacing were not affected. In the present paper the accumulation of the intermetallics b-Al5SiFe in the center of the samples due to RMF stirring is demonstrated numerically and the evolution of primary and secondary dendrite arm spacing is discussed.</jats:p

The effect of magnetically controlled fluid flow on microstructure Evolution in cast technical Al-alloys: The MICAST project

The ESA-MAP research program MICAST (Microstructure Formation in CASTing of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions) focuses on a systematic analysis of the effect of convection on microstructure evolution in cast Al-alloys. Questions are, for example, how intensity of convection and flow direction act on the evolution of the mushy zone, on macro- and micro-segregations, on dendrite morphology, on the growth mode and on spatial distribution of intermetallic precipitates. In order to simplify the complex interactions between heat and mass transport and microstructure evolution, the experiments performed by the MICAST team are carried out under well-defined thermally and magnetically controlled convective boundary conditions using directional solidification. They are analysed using advanced diagnostics and theoretical modelling, involving micro-modelling and global simulation of heat and mass transport. The MICAST team uses binary, ternary (enriched with Fe and Mn) and technical alloys of the industrially relevant Al Si cast alloys family. In the frame of the MICAST project solidification experiments were performed on the International Space Station (ISS) in the ESA payload Materials Science Laboratory (MSL) with a low gradient furnace (LGF) and a high(er) gradient one (SQF, Solidification and Quenching Furnace) to complement the scanning of a range of solidification times. Binary Al-7wt.%Si and ternary Al-7wt.%Si-1wt.%X (X=Fe, Mn) alloy samples were directionally solidified under both purely diffusive and stimulated convective conditions induced by a Rotating Magnetic Field (RMF). This contribution gives an overview on recent experimental results and theoretical modelling of the MICAST team and gives an outlook for the upcoming years of ISS experimentations by the team and the questions to be addressed with future experiments

The effect of magnetically controlled fluid flow on microstructure evolution in cast technical Alalloys: The MICAST project

International audienc

The effect of magnetically controlled fluid flow on microstructure evolution in cast technical Alalloys: The MICAST project

International audienc

MICAST – Microstructure Formation in Casting of technical alloys under diffusive and magnetically controlled convective conditions

The MICAST research program focuses on a systematic analysis of the effect of convection on the microstructure evolution in cast Al-alloys. The experiments of the MICAST team are carried out under well defined thermally and magnetically controlled, convective boundary conditions and analyzed using advanced diagnostics and theoretical modeling, involving phase field simulation, micro-modeling and global simulation of heat and mass transport. The MICAST team uses binary, ternary and technical alloys of the Al-Si family. This paper gives an overview on recent experimental results and theoretical modelling of the MICAST team