Silver sintering for power electronics integration

Silver sintering is an attractive alternative to soldering in power electronics, as it offers higher electrical and thermal performance. Furthermore, sintered attaches can operate at a higher temperature. In this paper, we investigate the use of silver sintering for the bonding of passive components, and for the manufacturing of so-called 3D-modules. It is shown that this technique is well suited, as it makes it possible to operate at very high temperature (up to 310 °C demonstrated), and as it simplifies the assembly process (several identical sintering steps can be performed successively without problem

Anisotropy expectations for ultra-high-energy cosmic rays with future high statistics experiments

UHECRs have attracted a lot of attention due to their challengingly high energies and their potential value to constrain physical processes and astrophysical parameters in the most energetic sources of the universe. Current detectors have failed to detect significant anisotropies which had been expected to allow source identification. Some indications about the UHECR composition, which may become heavier at the highest energies, has even put into question the possibility that such a goal could be achieved soon. We investigate the potential value of a new-generation detector, with 10 times larger exposure, to overcome the current situation and make significant progress in the detection of anisotropies and thus in the study of UHECRs. We take as an example the expected performances of the JEM-EUSO, assuming a uniform full-sky coverage with a total exposure of 300,000 km2 sr yr. We simulate realistic UHECR sky maps for a wide range of possible astrophysical scenarios allowed by the current constraints, taking into account the energy losses and photo-dissociation of the UHECRs, as well as their deflections by magnetic fields. These sky maps, built for the expected statistics of JEM-EUSO as well as for the current Auger statistics, as a reference, are analyzed from the point of view of their intrinsic anisotropies, using the two-point correlation function. A statistical study of the resulting anisotropies is performed for each astrophysical scenario, varying the UHECR source composition and spectrum as well as the source density. We find that significant anisotropies are expected to be detected by a next-generation UHECR detector, for essentially all the astrophysical scenarios studied, and give precise, quantitative meaning to this statement. Our results show that a gain of one order of magnitude in exposure would make a significant difference compared to the existing detectors.Comment: 26 pages, 28 figure

Modeling, Fabrication, and Characterization of Planar Inductors on YIG Substrates

International audienceThis paper presents the design, fabrication, and characterization of micro planar inductors on a microwave magnetic material (YIG). Planar spiral inductors were designed for monolithic DC-DC converters in System-In-Package with 100 MHz switching frequency (1 W, Vin= 3.6 V, Vout= 1 V). A microwave magnetic substrate (YIG) serves as mechanical support, and also presents a double purpose by increasing inductance value and reducing electromagnetic interferences (EMI). This last point is critical to improve the behavior of a switching mode power supply (SMPS). In order to obtain an optimal design for the inductor, geometrical parameters were studied using Flux2D simulator and an optimized 30 to 40 nH spiral inductor with expected 25 mΩ RDC, 3 mm2 footprint area was designed. Subsequently, samples have been fabricated by electroplating technique, and tested using a vector network analyzer in the 10 MHz to 100 MHz frequency range. Results were then compared to the predicted response of simulated equivalent model

Data availability and requirements relevant for the Ariel space mission and other exoplanet atmosphere applications

The goal of this white paper is to provide a snapshot of the data availability and data needs primarily for the Ariel space mission, but also for related atmospheric studies of exoplanets and cool stars. It covers the following data-related topics: molecular and atomic line lists, line profiles, computed cross-sections and opacities, collision-induced absorption and other continuum data, optical properties of aerosols and surfaces, atmospheric chemistry, UV photodissociation and photoabsorption cross-sections, and standards in the description and format of such data. These data aspects are discussed by addressing the following questions for each topic, based on the experience of the ‘data-provider’ and ‘data-user’ communities: (1) what are the types and sources of currently available data, (2) what work is currently in progress, and (3) what are the current and anticipated data needs. We present a GitHub platform for Ariel-related data, with the goal to provide a go-to place for both data-users and data-providers, for the users to make requests for their data needs and for the data-providers to link to their available data. Our aim throughout the paper is to provide practical information on existing sources of data whether in data bases, theoretical, or literature sources

Data availability and requirements relevant for the Ariel space mission and other exoplanet atmosphere applications

The goal of this white paper is to provide a snapshot of the data availability and data needs primarily for the Ariel space mission, but also for related atmospheric studies of exoplanets and brown dwarfs. It covers the following data-related topics: molecular and atomic line lists, line profiles, computed cross-sections and opacities, collision-induced absorption and other continuum data, optical properties of aerosols and surfaces, atmospheric chemistry, UV photodissociation and photoabsorption cross-sections, and standards in the description and format of such data. These data aspects are discussed by addressing the following questions for each topic, based on the experience of the "data-provider" and "data-user" communities: (1) what are the types and sources of currently available data, (2) what work is currently in progress, and (3) what are the current and anticipated data needs. We present a GitHub platform for Ariel-related data, with the goal to provide a go-to place for both data-users and data-providers, for the users to make requests for their data needs and for the data-providers to link to their available data. Our aim throughout the paper is to provide practical information on existing sources of data whether in databases, theoretical, or literature sources.Comment: 58 pages, submitted to RAS Techniques and Instruments (RASTI). The authors welcome feedback: corresponding author emails can be found as footnotes on page

Une approche sociologique des processus et conditions d'émergence du sentiment d'appartenance au territoire (l'exemple du pays de Brest)

L'approche sociologique du territoire se caractérise tant par les outils et méthodes qu'elle mobilise que par un regard qui prend en compte la spatialisation des rapports sociaux. Les grandes catégories conceptuelles de la sociologie comme les classes sociales et d'âge ou encore les groupes culturels sont particulièrment éclairantes pour comprendre les rapports individuels et collectifs au territoire. Pour le sociologue, le territoire humain s'étudie par les pratiques, les usages et les représentations des individus et groupes sociaux. Le territoire, et la manière dont les individus le perçoivent, le ressentent et l'utilisent témoignent d'une structuration sociale à l'oeuvre. Il faut donc considérer ces dimensions sociales, culturelles et identitaires qui interviennent dans l'émergence du sentiment d'appartenance au territoire. La recours à des méthodes d'objectivisation permettra de révéler les processus qui déterminent le sentiment d'appartenance. Ainsi, une approche biographique restituée dans son contexte territorial, associée à une étude de la mobilité à l'intérieur du pays de Brest comme révélatrice des territoires humains au quotidien semble-telle indiquée. Enfin, une étude des représentations du territoire permettra de mettre en parallèle les territoires objectivés par le sociologue et les territoires représentés par les individus et les groupes culturels et sociaux.The sociological approach of the territory is characterized so much by the tools and methods which it mobilizes that by a glance which takes into account the spatialization of the social reports. Main conceptual categories of sociology like the social classes and age or the cultural groups are particularly lighting to understand the individual and collective reports with the territory. For the sociologist, the human territory is studied by the practices, the uses and the representations of the individuals and social groups. The territory, and the way in which the individuals perceive it, feel it and use it testify to a social structuring in action. It is thus necessary to consider these social, cultural and identify dimensions which intervene in the emergence of the feeling of membership of the territory. The recourse to methods of objectivation will take it possible to reveal the processes which determine the feeling of membership. Thus, a biographical approach put in perspective in its territorial context, associated to a study of the daily mobility inside the country of Brest like revealing of the human territories seems to be indicated. Lastly, a study of the representations of the territory will make it possible to put in parallel the territories objectified by the sociologist and the territories represented by the individuals and the cultural and social groups.BREST-BU Lettres (290192101) / SudocSudocFranceF