Utilisation d'ions lithium pour l'analyse des surfaces et des couches minces

Dans la tendance actuelle à utiliser des ions plus lourds que les particules α en rétrodiffusion élastique (domaine d'énergie de l'ordre du MeV), l'emploi d'ions lithium apparaît constituer une amélioration notable des caractéristiques essentielles de la méthode. Ceci est particulièrement vrai en ce qui concerne la résolution en profondeur, avec le maintien de la résolution des détecteurs, pour ce type d'ions. Nous présentons ici, en même temps qu'une étude comparative des performances analytiques des ions Li et d'autres particules, quelques applications en montrant l'intérêt dans l'étude des surfaces et des couches minces. Parmi les applications les plus caractéristiques, citons, pour des échantillons épais, l'étude simultanée de la composition des couches d'oxydation anodique formées à la surface d'aluminium et du comportement de l'impureté majeure du bain de formation. Dans les études de couches minces, outre la détermination précise de la stoechiométrie des couches diélectriques AlN, SiO, Al2O3, des effets d'implantation pourront être étudiés, comme l'oxygène dans les couches SiO

Possible fabrication techniques and welding specifications for the external cylinder of the CMS coil

The Compact Muon Solenoid (CMS) is one of the experiments, which are being designed in the framework of the Large Hadron Collider (LHC) project at CERN. The design field of the CMS magnet is 4 T, the magnetic length is 12.5 m and the free aperture is 6 m in diameter. This is achieved with a 4 layer and 5 module superconducting Al- stabilized coil energized at a nominal current of 20 kA at 4.5 K. In the CMS coil the structural function is ensured, unlike in other existing Al-stabilized thin solenoids, both by the Al-alloy reinforced conductor and the external cylinder. The calculated stress level in the cylinder at operating conditions is particularly severe. In this paper the different possible fabrication techniques are assessed and compared and a possible welding specification for this component is given. (9 refs)

Factors Influencing the Participation of Older People in Clinical Trials : Data Analysis from the MAVIS Trial

Peer reviewedPostprin

Pharmacological therapies in post stroke recovery: Recommendations for future clinical trials

Stroke is a leading cause of serious long-term disability in adults and is the second leading cause of death worldwide. Early reperfusion and neuroprotection techniques have been the focus of much effort with the aim of very acute treatment of the stroke. Targeting different mechanisms, pharmacological therapies have the potential to reduce disability in a large fraction of patients who survive the acute stroke. The brain's capacity to reorganize after stroke through plasticity mechanisms can be modulated by pharmacological agents. A number of therapeutic interventions are under study, including small molecules, growth factors, and monoclonal antibodies. Recently it has been shown that the SSRI fluoxetine improved motor deficit in patients with ischaemic stroke and hemiplegia which appeared to be independent of the presence of depression. In this context, it is of major importance to support innovative research in order to promote the emergence of new pharmacological treatments targeting neurological recovery after stroke, as opposed to acute de-occlusion and neuroprotection. This paper is the work of a group of 14 scientists with aim of (1) addressing key areas of the basic and clinical aspects of human brain plasticity after stroke and potential pharmacological targets for recovery, (2) asking questions about the most appropriate characteristics of clinical trials testing drugs in post stroke recovery and (3) proposing recommendations for future clinical trials. © 2013 Springer-Verlag Berlin Heidelberg

Intervention and revision: Expertise and interaction in text mediation

Many EAL (English as an Additional Language) scholars enlist text mediators’ support when faced with the challenges of writing for international publication. However, the contributions these individuals are able to make in improving scientific manuscripts remains unclear, especially when language professionals such as English teachers do this work. In this article, we explore this topic by examining how three mediators employed their very different expertise and brought different processes to bear on the same discussion section of a medical manuscript written by a novice scholar in China. We find that successfully mediated texts are often the result of an interplay between the mediator’s expertise and the relationship between the participants. Our findings contradict those of previous studies that question the role of English teachers in this process and have the potential to inform both text mediation practices and revision studies

A Magnified View: The Impact of Arts Integration in the ELA and Social Studies Classroom

This qualitative research study explores the impact of arts integration in the ELA and social studies classroom. Through interdisciplinary lessons that weave music, theater, visual art, and movement with ELA and social studies content; this research explores the result of arts integration in the classroom. The fourth grade student participants in this study have contributed their ideas, understanding and reflections of the interdisciplinary ELA and social studies lessons through a collection of work samples, surveys, and interviews. Although the New York State Common Core State Standards have created a shift in content priorities and objectives for teachers, this study examines the impact on student learning through thoughtful arts integration.SUNY BrockportEducation and Human DevelopmentMaster of Science in Education (MSEd)Education and Human Development Master's These

A Magnified View: The Impact of Arts Integration in the ELA and Social Studies Classroom

This qualitative research study explores the impact of arts integration in the ELA and social studies classroom. Through interdisciplinary lessons that weave music, theater, visual art, and movement with ELA and social studies content; this research explores the result of arts integration in the classroom. The fourth grade student participants in this study have contributed their ideas, understanding and reflections of the interdisciplinary ELA and social studies lessons through a collection of work samples, surveys, and interviews. Although the New York State Common Core State Standards have created a shift in content priorities and objectives for teachers, this study examines the impact on student learning through thoughtful arts integration

Imaging Oxygen Distribution in Marine Sediments. The Importance of Bioturbation and Sediment Heterogeneity

The influence of sediment oxygen heterogeneity, due to bioturbation, on diffusive oxygen flux was investigated. Laboratory experiments were carried out with 3 macrobenthic species presenting different bioturbation behaviour patterns:the polychaetes Nereis diversicolor and Nereis virens, both constructing ventilated galleries in the sediment column, and the gastropod Cyclope neritea, a burrowing species which does not build any structure. Oxygen two-dimensional distribution in sediments was quantified by means of the optical planar optode technique. Diffusive oxygen fluxes (mean and integrated) and a variability index were calculated on the captured oxygen images. All species increased sediment oxygen heterogeneity compared to the controls without animals. This was particularly noticeable with the polychaetes because of the construction of more or less complex burrows. Integrated diffusive oxygen flux increased with oxygen heterogeneity due to the production of interface available for solute exchanges between overlying water and sediments. This work shows that sediment heterogeneity is an important feature of the control of oxygen exchanges at the sediment–water interface

The partial oxidation of methane over Pd/Al2O3 catalyst nanoparticles studied in-situ by near ambient-pressure x-ray photoelectron spectroscopy

Near ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) is used to study the chemical state of methane oxidation catalysts in-situ. Al2O3{supported Pd catalysts are prepared with different particle sizes ranging from 4 nm to 10 nm. These catalysts were exposed to conditions similar to those used in the partial oxidation of methane (POM) to syn-gas and simultaneously monitored by NAP-XPS and mass spectrometry. NAP-XPS data show changes in the oxidation state of the palladium as the temperature in- creases, from metallic Pd0 to PdO, and back to Pd0. Mass spectrometry shows an increase in CO production whilst the Pd is in the oxide phase, and the metal is reduced back under presence of newly formed H2. A particle size effect is observed, such that CH4 conversion starts at lower temperatures with larger sized particles from 6 nm to 10 nm. We find that all nanoparticles begin CH4 conversion at lower temperatures than polycrystalline Pd foil