Complex temperature dependence of coupling and dissipation of cavity-magnon polaritons from milliKelvin to room temperature

Hybridized magnonic-photonic systems are key components for future information processing technologies such as storage, manipulation or conversion of data both in the classical (mostly at room temperature) and quantum (cryogenic) regime. In this work, we investigate a YIG sphere coupled strongly to a microwave cavity over the full temperature range from $290\,\mathrm{K}$ down to $30\,\mathrm{mK}$. The cavity-magnon polaritons are studied from the classical to the quantum regime where the thermal energy is less than one resonant microwave quanta, i.e. at temperatures below $1\,\mathrm{K}$. We compare the temperature dependence of the coupling strength $g_{\rm{eff}}(T)$, describing the strength of coherent energy exchange between spin ensemble and cavity photon, to the temperature behavior of the saturation magnetization evolution $M_{\rm{s}}(T)$ and find strong deviations at low temperatures. The temperature dependence of magnonic disspation is governed at intermediate temperatures by rare earth impurity scattering leading to a strong peak at $40\,$K. The linewidth $\kappa_{\rm{m}}$ decreases to $1.2\,$MHz at $30\,$mK, making this system suitable as a building block for quantum electrodynamics experiments. We achieve an electromagnonic cooperativity in excess of $20$ over the entire temperature range, with values beyond $100$ in the milliKelvin regime as well as at room temperature. With our measurements, spectroscopy on strongly coupled magnon-photon systems is demonstrated as versatile tool for spin material studies over large temperature ranges. Key parameters are provided in a single measurement, thus simplifying investigations significantly.Comment: 10 pages , 9 figures in tota

La traçabilité de l'électricité : une méthode équitable pour l'allocation des coûts de transmission

International audienceDans le contexte international de l'ouverture des marchés de l'électricité, le volume croissant d'échanges ne permet leur tarification équitable que par le biais d'une estimation des responsabilités physiques des acteurs. Or, du fait de l'impossibilité d'affecter « physiquement » les transits aux acteurs, différentes méthodes peuvent être utilisées. Soucieux de définir une traçabilité équitable, ce papier présente une nouvelle méthode pour déterminer les échanges bilatéraux équivalents entre générateurs et consommateurs. Elle est basée sur le calcul de distances électriques équivalentes et la prise en compte des pertes dans la répartition. Ses résultats sont présentés et comparés à ceux d'autres méthodes de traçabilité dans le cas d'un réseau standard

Visualising the dynamics of character networks

The character network of a given narrative (novel, play, film, graphic novel, etc.) models the structure formed by the relations in its character-system (Woloch, 2003). A relation between two characters symbolises their co-presence in parts of the narrative; the entire set of relations between all characters constitutes a formal model of this character-system and lends itself to display and analysis. For example, Moretti (2011) used network modelling to compare the importance of protagonists from Shakespeare's Hamlet, while Trilcke et al. (2015) created character networks for 465 German plays and used them to initiate a wider study of German Theatre. Most applications of character network analysis have disregarded temporality, possibly because of its representational complexity. Consequently, all relations in the system are considered as happening at the same time: one cannot distinguish if a given edge symbolises a relation at the start, at the end, or in several parts of the work under study. Furthermore, because temporality is not being accounted for, there is usually no way of relating the network visualisation with the unfolding of the source narrative. While prototypes such as those discussed in Roberts-Smith et al. (2013) offer sophisticate ways of dynamically visualising the text of theatre plays, they do so in a way that is unrelated to character network modelling. Based on these observations, we set out to develop an open source web application which models the character-system of theatre plays as a sequence of network states synchronised with the actual narrative content (https://github.com/maladesimaginaires/intnetviz). This paper proposes a high-level overview of our application , successively focusing on the underlying structure extraction process, the conception of the graphical interface, and the range of uses envisioned for it. In the conclusion, we evoke the ways in which we intend to develop it and reflect on the potential significance of this development at a more epistemological level

Développement d'assemblages de dispositif de retenue pour les ponts à tabliers orthotropes en acier

Les dispositifs de retenue sur les ouvrages d’art fournissent une protection essentielle aux usagers de la route. Ils atténuent les conséquences d’une perte de contrôle d’un véhicule en empêchant sa sortie de la voie carrossable ou son intrusion dans une voie inverse. Actuellement, les standards nord-américains de conception d’ouvrages d’art requièrent que la résistance et le comportement sécuritaire des dispositifs soient prouvés par un essai de collision à grandeur réelle. Un dispositif de retenue préalablement testé et accepté peut être modifié si le responsable peut démontrer sa performance par des analyses et des simulations appropriées. La méthode des éléments finis est un outil efficace pour prédire la réponse d’un dispositif de retenue sous les charges induites par l’impact d’un véhicule. Le présent projet de recherche vise à développer des détails d’assemblages génériques (montés directement sur le tablier et sur un chasse-roue) permettant d’assembler un dispositif de retenue de type poteaux-poutres en acier déjà testé et approuvé aux tabliers orthotropes en acier les plus récemment développés. Ce projet implique des analyses statiques et des simulations dynamiques en utilisant ABAQUS et LS-DYNA, respectivement. La capacité de l’assemblage à transférer la charge d’impact sans compromettre l’intégrité structurale du tablier de pont et du dispositif lui-même est examinée en détail. Des détails d’assemblage ont été développés avec un système de plaques de renfort et un module d’assemblage pour assembler les dispositifs de retenue directement sur le tablier orthotrope et sur un chasse-roue en acier, respectivement. Des similitudes entre les résultats des différentes analyses montrent que les charges statiques spécifiées par la norme CSA S6-06 sont appropriées pour la modification des ancrages de dispositifs de retenue pour les assembler à des tabliers orthotropes en acier. Mots clés : Dispositif de retenue, tablier orthotrope en acier, pont routier, assemblage, analyse par éléments finis.Traffic barriers in bridge construction are specially designed devices that are carefully selected and connected to the bridge deck to redirect errant vehicles safely into the flow of traffic and prevent them from proceeding down a non-driveable batter. Current North American bridge design standards require that the selected traffic barrier system must be crash-tested at full-scale to ensure a safe design standard. Minimal modifications of already crash-tested and approved traffic barrier system are however allowed if its performance can be demonstrated by an appropriate engineering simulation and analysis. The finite element analysis method is an effective tool to predict the response of traffic barriers under vehicle-induced forces. The present research aims at developing generic connector systems (deck and curb-mounted) that allows the attachment of a standard already-crash-tested post-and-rail barrier to orthotropic steel decks. This research involves both static analysis and dynamic simulation of crash-test using ABAQUS and LS-DYNA. The ability of the attachment system to transfer the impact loads without compromising the structural integrity of the bridge deck or the barrier itself would be examined in detail. Typical assembly were developed with strengthening plates to connect the traffic barriers directly on the orthotropic steel deck and with a module to connect it on a steel curb. Similarities existing between the results of the different analyses show that the static loads specified in Canadian standard CSA S6-06 are appropriate for the modification of the anchorage of traffic barriers to connect them to orthotropic steel decks. Keywords : Traffic barrier, orthotropic steel deck, bridge, connector system, finite element analysis

Software in the Manufacturing Industry: A Review of Security Challenges and Implications

Software defines digital infrastructures in the manufacturing industry, connecting services and computation resources to machines and devices. These infrastructures aim at increased flexibility, scalability, and a wider application portfolio for automated manufacturing processes. At the same time, the complexity of securing software increases dramatically. Threats to confidentiality, integrity, and availability of software can result in critical losses for automated industrial production and impact manufacturing companies. In order to map existing and emerging security challenges, we present the results of a hermeneutic literature review structured along abstraction levels and vertical integration of software. Based on this structure, we derive implications for academia and practice focused on operators, developers, and security auditors of digital infrastructures. Thereby, we discuss courses of action mapped to software security black boxes, infrastructure heterogeneity, and the adaptation of security for operational usage

Prevalence of Inherited Hemoglobin Disorders and Relationships with Anemia and Micronutrient Status among Children in Yaoundé and Douala, Cameroon.

Information on the etiology of anemia is necessary to design effective anemia control programs. Our objective was to measure the prevalence of inherited hemoglobin disorders (IHD) in a representative sample of children in urban Cameroon, and examine the relationships between IHD and anemia. In a cluster survey of children 12-59 months of age (n = 291) in Yaoundé and Douala, we assessed hemoglobin (Hb), malaria infection, and plasma indicators of inflammation and micronutrient status. Hb S was detected by HPLC, and α⁺thalassemia (3.7 kb deletions) by PCR. Anemia (Hb < 110 g/L), inflammation, and malaria were present in 45%, 46%, and 8% of children. A total of 13.7% of children had HbAS, 1.6% had HbSS, and 30.6% and 3.1% had heterozygous and homozygous α⁺thalassemia. The prevalence of anemia was greater among HbAS compared to HbAA children (60.3 vs. 42.0%, p = 0.038), although mean Hb concentrations did not differ, p = 0.38). Hb and anemia prevalence did not differ among children with or without single gene deletion α⁺thalassemia. In multi-variable models, anemia was independently predicted by HbAS, HbSS, malaria, iron deficiency (ID; inflammation-adjusted ferritin <12 µg/L), higher C-reactive protein, lower plasma folate, and younger age. Elevated soluble transferrin receptor concentration (>8.3 mg/L) was associated with younger age, malaria, greater mean reticulocyte counts, inflammation, HbSS genotype, and ID. IHD are prevalent but contribute modestly to anemia among children in urban Cameroon

Probing the stellar populations of early-type galaxies: the SAURON survey

The SAURON project will deliver two-dimensional spectroscopic data of a sample of nearby early-type galaxies with unprecedented quality. In this paper, we focus on the mapping of their stellar populations using the SAURON data, and present some preliminary results on a few prototypical cases.Comment: 12 pages, 6 figures. ASP Conference, Galaxies: the Third Dimension, Cozumel. Version with higher resolution figures available at http://www-obs.univ-lyon1.fr/eric.emsellem/papers/cozumel_emsellem.ps.g