Ab initio calculation of spin-dependent electron-phonon coupling and transport in iron and cobalt

in Journal of Physics : Condensed Matter (2013), 25

The spin-dependent coupling between electrons and phonons in ferromagnetic Fe and Co is calculated from first principles in a collinear-spin formalism. The added spin polarization is fundamental for the ... [more ▼]

The spin-dependent coupling between electrons and phonons in ferromagnetic Fe and Co is calculated from first principles in a collinear-spin formalism. The added spin polarization is fundamental for the correct representation of the phonons, but also to obtain good transport properties, and permits the decomposition (e.g. of the resistivity) into the contributions of majority and minority spin. In Fe the minority spin coupling is only about 50\% more important, but in Co the coupling between phonons and minority spin electrons is an order of magnitude larger than majority, and both are strongly anisotropic. [less ▲]

Changes in naming and semantic abilities with aging from 50 to 90 years

in Journal of the International Neuropsychological Society (2013)

The aim of this study was to determine whether naming difficulties arise in individuals as young as their 50s. Participants of 25-35, 50-59, 60-69 and above 70 years of age were given a picture naming ... [more ▼]

The aim of this study was to determine whether naming difficulties arise in individuals as young as their 50s. Participants of 25-35, 50-59, 60-69 and above 70 years of age were given a picture naming task. To uncover subtle naming difficulties, latencies were analyzed in addition to accuracy. In order to control whether the expected slower naming latencies could be due to a general slowing affecting all cognitive tasks, participants were also given an odd/even judgment task to assess cognitive processing speed. The results confirmed that participants in their 50s presented decline in naming performance, reflected by an increase in naming latencies, whereas adults in their 60s and their 70s showed both a decrease in accuracy and an increase in latency. Moreover, the increase in naming latencies remained significant even after controlling for odd/even judgment latencies, suggesting a degradation specific to the picture naming task. We assumed that these slower latencies may result from a language-specific impairment. As a further test for language-specific degradation, participants’ semantic capacities were also assessed with a synonym judgment task and the Pyramids and Palm Trees test. The above-70 group showed semantic degradation. The contributions of multiple factors to naming difficulties in aging are discussed. [less ▲]

Les permis ratifiés par le législateur en Région wallonne (« DAR ») mis en échec par la Cour de justice de l’Union européenne et la Cour constitutionnelle

E-print/Working paper (2013)

A propos d'une réforme de la fiscalité immobilière

Report (2013)

Cette contribution a pour objectif de stimuler la discussion relative à la réforme du régime de la fiscalité immobilière en Belgique. Les auteurs y exposent le contexte juridique dans lequel s'inscrit une ... [more ▼]

Cette contribution a pour objectif de stimuler la discussion relative à la réforme du régime de la fiscalité immobilière en Belgique. Les auteurs y exposent le contexte juridique dans lequel s'inscrit une telle réforme, ainsi que les enjeux principaux à prendre en considération. Une série de propositions sont également énoncées. [less ▲]

Poétique à quatre mains : les suites dialogiques d’Izoard et Savitzkaya

in Textyles : Revue des Lettres Belges de Langue Française (2013)

Apollinaire et la rime (deuxième partie)

in Apollinaire (2013), 13

Efficient Pt/carbon electrocatalysts for Proton Exchange Membrane fuel cells: avoid chloride-based Pt salts !

in Journal of Power Sources (2013), 240

High-resolution modelling of the Antarctic surface mass balance, application for the 20th, 21st and 22nd centuries

E-print/Working paper (2013)

About 75% of the Antarctic surface mass gain occurs over areas below 2000 m asl, which cover 40% of the grounded ice-sheet. As the topography is complex in many of these regions, SMB modelling is highly ... [more ▼]

About 75% of the Antarctic surface mass gain occurs over areas below 2000 m asl, which cover 40% of the grounded ice-sheet. As the topography is complex in many of these regions, SMB modelling is highly dependent on resolution, and studying the impact of Antarctica on the future rise in sea level requires physical approaches. We have developed a low time consuming, physical downscaling model for high-resolution (15 km) long-term surface mass balance (SMB) projections. Here, we present results of this model, called SMHiL (surface mass balance high-resolution downscaling), which was forced with the LMDZ4 atmospheric general circulation model to assess SMB variation in the 21st and the 22nd centuries under two different scenarios. The higher resolution of SMHiL better reproduces the geographical patterns of SMB and increase significantly the averaged SMB over the grounded ice-sheet for the end of the 20th century. A comparison with more than 3200 quality-controlled field data shows that LMDZ4 and SMHiL compare the observed values equally well. Nevertheless, field data below 2000 m asl are too scarce to efficiency show the interest of SMHiL and measuring the SMB in these undocumented areas should be then a future scientific priority. Our results suggest that running LMDZ4 at a finer resolution (15km) may give a future increase in SMB in Antarctica about 30% higher than by using its standard resolution (60 km) due to higher increase in precipitation in the coastal areas at 15 km. However, a part (~ 15%) of these discrepancies could be an artefact from SMHiL since it neglects the foehn effect and then likely overestimates the precipitation increase. Future changes in the Antarctic SMB at low elevations will result from the conflict between higher snow accumulation and runoff. For this reason, developing downscaling models is crucial to represent processes in sufficient detail and correctly model the SMB in the coastal areas. [less ▲]

Fast microwave assisted extraction of rotenone for its quantification in seeds of yam bean (Pachyrhizus sp.)

in Journal of Separation Science (2013), 36

The aim of this study was to find if fast microwave assisted extraction could be an alternative to the conventional soxhlet extraction for the quantification of rotenone in yam bean seeds by solid phase ... [more ▼]

The aim of this study was to find if fast microwave assisted extraction could be an alternative to the conventional soxhlet extraction for the quantification of rotenone in yam bean seeds by solid phase extraction and HPLC-UV. For this purpose, an experimental design was used to determine the optimal conditions of the microwave extraction. Then the values of the quantification on three accessions from two different species of yam bean seeds were compared using the two different kinds of extraction. A microwave extraction of 11 min at 55°C using methanol/dichloromethane (50:50) allowed rotenone extraction either equivalently or more efficiently than the 8h soxhlet extraction method and was less sensitive to moisture content. The selectivity, precision, trueness, accuracy and limit of quantification of themethod with microwave extraction were also demonstrated. [less ▲]

Optimal Fertility along the Lifecycle

in Economic Theory (2013)