Energy transferred to the substrate surface during reactive magnetron sputtering of aluminum in Ar/O2 atmosphere

International audienceA study of the reactive sputtering of aluminum was carried out by coupling energy flux measurements at the substrate location with conventional diagnostics of the gas phase and analyses of the deposited films. The main purpose was to get some insight into the elementary mechanisms involved at the substrate surface during the film growth in the well known metal and oxide regimes and at the transitions from one to another. Measurements were carried out in front of a 10 cmAl target at a power of 400W (i.e. 5 W/cm2) and a total pressure of 0.6 Pa. The flow rate ratio (O2/O2+Ar) was varied in the range 0 to 50 %. Different kinetics and values of energy transfer, denoting different involved mechanisms, were evidenced at metal-oxide (increasing flow rate) and oxide-metal (decreasing flow rate) transitions. The metal-oxide transition was found to be a progressive process, in agreement with optical emission spectroscopy and deposit analysis, characterized by an increase of the energy flux that could be due to the oxidation of the growing metal film. On the contrary, oxide-metal transition is abrupt, and a high energy released at the beginning that could not be attributed to a chemical reaction. The possible effect of O-ions at this step was discussed

Influence of step structure on preferred orientation relationships of Ag deposited on Ni(111)

Previous studies have shown that the orientation relationships which develop in hetero-epitaxy are strongly influenced by the alignment of steps in the deposit with the pre-existing steps of the substrate. In this paper we use a combination of experiments with computer simulations to identify the important influence of substrate step structure on the eventual orientation relationships that develop in the deposit. We have made use of Ag deposited on Ni as it has been used extensively as a model system for the study of hetero-epitaxy. This system displays a large lattice mismatch of 16%. It is shown that on any surface vicinal to Ni(111), which has two possible kinds of steps (A-steps with {100} ledges and B-steps with {111} ledges), a Ag deposit adopts a single orientation relationship because only A-steps remain stable in the presence of Ag.Comment: Acta Materialia, Elsevier, In pres

Decim v2

The original publication is available at www.springerlink.comIn this paper, we present Decimv2, a stream cipher hardware- oriented selected for the phase 3 of the ECRYPT stream cipher project eSTREAM. As required by the initial call for hardware-oriented stream cipher contribution, Decimv2 manages 80-bit secret keys and 64-bit public initialization vectors. The design of Decimv2 combines two filtering mechanisms: a nonlinear Boolean filter over a LFSR, followed by an irregular decimation mechanism called the ABSG. Since designers have been invited to demonstrate flexibility of their design by proposing vari-ants that take 128-bit keys, we also present a 128-bit security version of Decim called Decim-128

Death and the Societies of Late Antiquity

Ce volume bilingue, comprenant un ensemble de 28 contributions disponibles en français et en anglais (dans leur version longue ou abrégée), propose d’établir un état des lieux des réflexions, recherches et études conduites sur le fait funéraire à l’époque tardo-antique au sein des provinces de l’Empire romain et sur leurs régions limitrophes, afin d’ouvrir de nouvelles perspectives sur ses évolutions possibles. Au cours des trois dernières décennies, les transformations considérables des méthodologies déployées sur le terrain et en laboratoire ont permis un renouveau des questionnements sur les populations et les pratiques funéraires de l’Antiquité tardive, période marquée par de multiples changements politiques, sociaux, démographiques et culturels. L’apparition de ce qui a été initialement désigné comme une « Anthropologie de terrain », qui fut le début de la démarche archéothanatologique, puis le récent développement d’approches collaboratives entre des domaines scientifiques divers (archéothanatologie, biochimie et géochimie, génétique, histoire, épigraphie par exemple) ont été décisives pour le renouvellement des problématiques d’étude : révision d’anciens concepts comme apparition d’axes d’analyse inédits. Les recherches rassemblées dans cet ouvrage sont articulées autour de quatre grands thèmes : l’évolution des pratiques funéraires dans le temps, l’identité sociale dans la mort, les ensembles funéraires en transformation (organisation et topographie) et les territoires de l’empire (du cœur aux marges). Ces études proposent un réexamen et une révision des données, tant anthropologiques qu’archéologiques ou historiques sur l’Antiquité tardive, et révèlent, à cet égard, une mosaïque de paysages politiques, sociaux et culturels singulièrement riches et complexes. Elles accroissent nos connaissances sur le traitement des défunts, l’emplacement des aires funéraires ou encore la structure des sépultures, en révélant une diversité de pratiques, et permettent au final de relancer la réflexion sur la manière dont les sociétés tardo-antiques envisagent la mort et sur les éléments permettant d’identifier et de définir la diversité des groupes qui les composent. Elles démontrent ce faisant que nous pouvons véritablement appréhender les structures culturelles et sociales des communautés anciennes et leurs potentielles transformations, à partir de l’étude des pratiques funéraires.This bilingual volume proposes to draw up an assessment of the recent research conducted on funerary behavior during Late Antiquity in the provinces of the Roman Empire and on their borders, in order to open new perspectives on its possible developments. The considerable transformations of the methodologies have raised the need for a renewal of the questions on the funerary practices during Late Antiquity, a period marked by multiple political, social, demographic and cultural changes. The emergence field anthropology, which was the beginning of archaeothanatology, and then the recent development of collaborative approaches between various scientific fields (archaeothanatology, biochemistry and geochemistry, genetics, history, epigraphy, for example), have been decisive. The research collected in this book is structured around four main themes: Evolution of funerary practices over time; Social identity through death; Changing burial grounds (organisation and topography); Territories of the Empire (from the heart to the margins). These studies propose a review and a revision of the data, both anthropological and archaeological or historical on Late Antiquity, and reveal a mosaic of political, social, and cultural landscapes singularly rich and complex. In doing so, they demonstrate that we can truly understand the cultural and social structures of ancient communities and their potential transformations, based on the study of funerary practices

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Un système de dictionnaires électroniques pour les mots simples du français

Courtois Blandine. Un système de dictionnaires électroniques pour les mots simples du français. In: Langue française, n°87, 1990. Dictionnaires électroniques du français, sous la direction de Blandine Courtois et Max Silberztein. pp. 11-22

Dictionnaires électroniques DELAF anglais et français

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Dictionnaires électroniques du français

Courtois Blandine, Silberztein Max. Dictionnaires électroniques du français. In: Langue française, n°87, 1990. Dictionnaires électroniques du français, sous la direction de Blandine Courtois et Max Silberztein. pp. 3-4

Dictionnaires électroniques du français

Courtois Blandine, Silberztein Max. Dictionnaires électroniques du français. In: Langue française, n°87, 1990. Dictionnaires électroniques du français, sous la direction de Blandine Courtois et Max Silberztein. pp. 3-4

Procédé de préparation de films minces monocristallins

The invention relates to a process for preparing single-crystal thin films of pure metals or alloys, by deposition and growth of grains on a (0001) sapphire having a miscut comprised between 0.2° and 5°, and oriented towards a specific plane. It also relates to a single-crystal thin film obtainable by such a process and uses thereof.L'invention concerne un procédé de préparation de films minces monocristallins de métaux ou d'alliages purs, par dépôt et croissance de grains sur un saphir (0001) présentant une mauvaise découpe comprise entre 0,2° et 5°, et orientés vers un plan spécifique. L'invention concerne également un film mince monocristallin pouvant être obtenu par un tel procédé et ses utilisations