968 research outputs found
The Role Of Tax And Transfers In Reducing Personal Income Inequality In EuropeÃs Regions: Evidence From EUROMOD
In this paper we use statistical tools and graphic devices in order to give a comprehensive picture of income inequality levels in a set of 100 EU-15 regions at the end of the XX century before and after the operation of the tax-benefit. Our analysis is based on EUROMOD, the first multi-country tax-benefit model built with a common framework that includes detailed information on taxes and benefits paid and received by individuals and/or households from samples that are representative for the 15 EU countries. Our analysis focuses on intraregional inequality and it explores the relationship between regional inequality levels (both in market incomes and disposable incomes) and economic performance. Our main findings indicate that tax-benefits systems in Europe notably reduce market inequality in all EU regions and that the size of this reduction (i.e. redistributive effect) depends crucially on (i) the market inequality level of the region (positively), (ii) the relative economic performance of the region in the country (negatively) and (iii) the country to which the region belongs.European Union, Regions, inequality, redistribution, economic performance
Atomistic and electronic structure of metal clusters supported on transition metal carbides: implications for catalysis
Novel research avenues have been explored over the last decade on the use of transition metal carbides (TMCs) as catalytically active supports for metal nanoclusters, which display high catalytic activity despite the poor reactivity (or even inertness) of the bulk metal. It has been postulated that TMCs polarise the electron density of adsorbed metal particles in such a way that their catalytic activity ends up being superior to those dispersed on more traditional metal oxide supports. Herein, we investigate the structural and electronic properties of small clusters of precious metals (Rh, Pd, Pt and Au) and more affordable metals (Co, Ni and Cu) supported on TMCs with 1:1 stoichiometry (TiC, ZrC, HfC, VC, NbC, TaC, MoC and WC) by means of periodic Density Functional Theory calculations. Our high-throughput screening studies indicate that it is possible not only to have strongly bonded and stably dispersed metal nanoparticles on TMC surfaces, but also to manipulate their charge by carefully selecting elements with desired electronegativity for the host TMC and the metal cluster. By doing so, it is possible to tune the amount of charge density on the cluster hollow sites, which can facilitate the bonding of certain molecules. Moreover, we identify Pt, Pd and Rh clusters supported on hexagonal TMC (001) facets as the candidates with the highest potential catalytic activity -as estimated by the significant polarisation of the cluster electron density- and stability -as quantified by the strongly negative values of adsorption energy per atom and formation energy
On global models for isolated rotating axisymmetric charged bodies; uniqueness of the exterior field
A relatively recent study by Mars and Senovilla provided us with a uniqueness
result for the exterior vacuum gravitational field generated by an isolated
distribution of matter in axial rotation in equilibrium in General Relativity.
The generalisation to exterior electrovacuum gravitational fields, to include
charged rotating objects, is presented here.Comment: LaTeX, 21 pages, uses iopart styl
Stationary axisymmetric exteriors for perturbations of isolated bodies in general relativity, to second order
Perturbed stationary axisymmetric isolated bodies, e.g. stars, represented by
a matter-filled interior and an asymptotically flat vacuum exterior joined at a
surface where the Darmois matching conditions are satisfied, are considered.
The initial state is assumed to be static. The perturbations of the matching
conditions are derived and used as boundary conditions for the perturbed Ernst
equations in the exterior region. The perturbations are calculated to second
order. The boundary conditions are overdetermined: necessary and sufficient
conditions for their compatibility are derived. The special case of
perturbations of spherical bodies is given in detail.Comment: RevTeX; 32 pp. Accepted by Phys. Rev. D. Added references and extra
comments in introductio
Selenium biofortification differentially affects sulfur metabolism and accumulation of phytochemicals in two rocket species (Eruca sativa mill. and diplotaxis tenuifolia) grown in hydroponics
Biofortification can be exploited to enrich plants in selenium (Se), an essential micronutrient for humans. Selenium as selenate was supplied to two rocket species, Eruca sativa Mill. (salad rocket) and Diplotaxis tenuifolia (wild rocket), at 0-40 \u3bcM in hydroponics and its effects on the content and profile of sulphur (S)-compounds and other phytochemicals was evaluated. D. tenuifolia accumulated more total Se and selenocysteine than E. sativa, concentrating up to ~300 mg Se kg 121 dry weight from 10-40 \u3bcM Se. To ensure a safe and adequate Se intake, 30 and 4 g fresh leaf material from E. sativa grown with 5 and 10-20 \u3bcM Se, respectively or 4 g from D. tenuifolia supplied with 5 \u3bcM Se was estimated to be optimal for consumption. Selenium supplementation at or above 10 \u3bcM differentially affected S metabolism in the two species in terms of the transcription of genes involved in S assimilation and S-compound accumulation. Also, amino acid content decreased with Se inE. sativa but increased in D. tenuifolia and the amount of phenolics was more reduced in D. tenuifolia. In conclusion, selenate application in hydroponics allowed Se enrichment of rocket. Furthermore, Se at low concentration (5 \u3bcM) did not significantly affect accumulation of phytochemicals and plant defence S-metabolites
Selenium biofortification differentially affects sulfur metabolism and accumulation of phytochemicals in two rocket species (Eruca sativa mill. and diplotaxis tenuifolia) grown in hydroponics
Spaceborne SAR attitude steering method for smart imaging mode
The current spaceborne synthetic aperture radar systems are operated to illuminate the scene along the satellite flying direction. However, in many cases, the interested areas are not parallel to the flying direction, so an innovative smart imaging mode is acquired, which can be employed for illuminating scene along a given direction. A novel three-axis attitude steering method is proposed for smart imaging mode. First, mathematical model of the attitude steering is built by considering the restrictive conditions of zero-Doppler centroid requirement and the position of interested area. Then, an iterative optimisation algorithm is designed to calculate the three-axis steering angles. Finally, experiment results using the satellite tool kit tool validate the proposed methods well, especially in the case of coastline imaging
Correlation Functions of Complex Matrix Models
For a restricted class of potentials (harmonic+Gaussian potentials), we
express the resolvent integral for the correlation functions of simple traces
of powers of complex matrices of size , in term of a determinant; this
determinant is function of four kernels constructed from the orthogonal
polynomials corresponding to the potential and from their Cauchy transform. The
correlation functions are a sum of expressions attached to a set of fully
packed oriented loops configurations; for rotational invariant systems,
explicit expressions can be written for each configuration and more
specifically for the Gaussian potential, we obtain the large expansion ('t
Hooft expansion) and the so-called BMN limit.Comment: latex BMN.tex, 7 files, 6 figures, 30 pages (v2 for spelling mistake
and added reference) [http://www-spht.cea.fr/articles/T05/174
Solvation of furfural at metal–water interfaces: Implications for aqueous phase hydrogenation reactions
Metal-water interfaces are central to understanding aqueous-phase heterogeneous catalytic processes. However, the explicit modeling of the interface is still challenging as it necessitates extensive sampling of the interfaces' degrees of freedom. Herein, we use ab initio molecular dynamics (AIMD) simulations to study the adsorption of furfural, a platform biomass chemical on several catalytically relevant metal-water interfaces (Pt, Rh, Pd, Cu, and Au) at low coverages. We find that furfural adsorption is destabilized on all the metal-water interfaces compared to the metal-gas interfaces considered in this work. This destabilization is a result of the energetic penalty associated with the displacement of water molecules near the surface upon adsorption of furfural, further evidenced by a linear correlation between solvation energy and the change in surface water coverage. To predict solvation energies without the need for computationally expensive AIMD simulations, we demonstrate OH binding energy as a good descriptor to estimate the solvation energies of furfural. Using microkinetic modeling, we further explain the origin of the activity for furfural hydrogenation on intrinsically strong-binding metals under aqueous conditions, i.e., the endothermic solvation energies for furfural adsorption prevent surface poisoning. Our work sheds light on the development of active aqueous-phase catalytic systems via rationally tuning the solvation energies of reaction intermediates
- …