Filtre Dual Behavior Resonator (DBR) à réponse plate en bande C

National audienceIl existe de nombreuses méthodes de synthèse plus ou moins générales, et plus ou moins adaptées à l'utilisation de matrice de couplage. Certaines sont facilement programmables, d'autres demandent une mise en oeuvre beaucoup plus lourde. Nous exposerons dans ce papier, la méthode développée par Zabalawi [1] que l'on adaptera à une topologie particulière du filtre DBR. Cette méthode, valable pour un ordre 6 permet d'avoir des filtres à temps de propagation de groupe le plus plat possible dans la bande passante c'est-à-dire à phase linéaire. La maîtrise simultanée de la phase et de l'amplitude impose d'utiliser des filtres à phase non minimum, c'est-à-dire possédant un ou plusieurs zéros de transmission complexes ou réels, localisés dans le demiplan droit du plan complexe. Dans un premier temps, nous expliquerons brièvement le principe de fonctionnement de cette topologie particulière. Ensuite, nous exposerons la procédure de synthèse à partir de la matrice nodale jusqu'à la réalisation du circuit. Cette représentation matricielle particulière se distinguant des représentations classiques

Coupleur de Lange Multicouche en bande Ka

National audienceLa technologie multicouche offre une grande flexibilité dans la réalisation des dispositifs passifs hyperfréquences. En effet, elle permet de s'affranchir de certaines limitations intrinsèques aux filières planaires classiques (e.g. gamme d'impédances caractéristiques, gamme de couplages). Nous décrivons dans ce papier la réalisation d'un coupleur de Lange en technologie multicouche afin de montrer la faisabilité du concept et la potentialité de ce type de technologie en bande Ka. Des résistances sérigraphiées sont gravées sur le circuit pour faire office de charges adaptées nécessaires pour les mesures

Filtre multicouche en bande C à résonateurs en boucle-ouverte carrée et plots métalliques flottants

National audienceL'évolution constante et rapide des systèmes de télécommunications conduit à rechercher des solutions hyperfréquences faibles coûts toujours plus performantes et de taille réduite. Afin de satisfaire aux spécifications très sévères des filtres, il est nécessaire d'associer des topologies adéquates, des outils de simulation précis et une technologie maîtrisée. A cet effet, les topologies à base de couplages croisés qui permettent de favoriser les couplages entre résonateurs non adjacents pour améliorer les performances, sont très attractives [1]. Une grande variété de formes de résonateurs planaires a été développée mais généralement implémentée pour des applications de filtre à bande étroite. En effet, pour des filtres plus large bande, des niveaux de couplage plus élevés sont nécessaires, ce qui se traduit par des distances inter-résonateurs très faibles. Une solution pratique pour résoudre cette difficulté est d'utiliser des structures multi niveaux [2]. Dans la littérature, la plupart des filtres multicouches décrits sont à bande étroite (bande passante relative inférieure à 10%), et l'objectif est clairement la réduction de taille. Cet article décrit un filtre présentant une bande passante de 22% et utilisant des résonateurs en boucle ouverte. Les niveaux élevés de couplage sont réalisés en considérant deux niveaux conducteurs et des plots métalliques flottants [3]. Notre objectif est d'illustrer les bénéfices d'une technologie multicouche au travers de la conception d'un filtre large-bande basée sur une approche de type matrice de couplage

Exploitation des couplages de proximité dans une topologie de filtres à stubs

National audienceParmi les nombreuses topologies de filtres décrites dans la littérature, la topologie Dual Behavior Resonator (DBR) apporte de nombreux avantages [1]. Elle permet un contrôle indépendant et simultané de la fréquence centrale et des bandes atténuées adjacentes. Ses caractéristiques particulières, ses degrés de liberté et sa souplesse, lui permettent de répondre aisément à des spécifications électriques sévères. Toutefois, comme pour les autres topologies classiques de filtres à stubs, un phénomène n'est pas pris en compte dans la synthèse : il s'agit des couplages de proximité apparaissant de façon fortuite entre les résonateurs adjacents ou non adjacents. Ces couplages non pris en compte par les synthèses traditionnelles influent beaucoup sur la réponse électrique des structures, et peuvent être de surcroît de nouveaux paramètres de réglage. Ce papier est consacré à l'exploitation des phénomènes de couplage pour améliorer les performances de la topologie DBR. Cela nécessite de définir et de mettre en oeuvre des techniques de synthèse adaptées pour maîtriser ces phénomènes

New bioelectrical impedance vector references and phase angle centile curves in 4,367 adults: The need for an urgent update after 30 years

Background & aims: The bioelectrical impedance vector analysis (BIVA) represents a qualitative analysis of body composition. The vector, defined by resistance (R) and reactance (Xc) standardized by stature, can be evaluated compared to the 50%,75%, and 95% tolerance ellipses representative of the reference populations. The tolerance ellipses for healthy adults have been provided in 1995 and were developed by mixing underage, adult, and elderly subjects, possibly misrepresenting the actual adult population. The current multicentric, cross-sectional study aimed to provide new tolerance ellipses specific for the general adult population and as a secondary aim to present centile curves for the bioelectrical phase angle. Methods: R, Xc, and phase angle were measured in 2137 and 2230 males and females using phase-sensitive foot-to-hand analyzers at 50 kHz. A minimum of 35 subjects were included for each sex and age category from 18 to 65 years. Results: The new mean vectors showed a leftward shift on the R-Xc graph with respect to the former reference values (males: F = 75.3; p < 0.001; females: F = 36.6, p < 0.001). The results provided new 3rd, 5th, 10th, 25th, 50th, 75th, 90th, 95th, and 97th percentile curves for phase angle, identifying time point phases of decrement (males: -0.03° per year at 33.0-51.0 years and -0.05° per year after 51 years; females: -0.03° per year from 37.2 to 57.9 years). Conclusions: Compared to the original references, the new data are characterized by a different distribution within the R-Xc graph with a higher phase angle. Thirty years after the BIVA invention, the current study presents new tolerance ellipses and phase angle reference values for the adult population

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

Search for stop and higgsino production using diphoton Higgs boson decays

Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top-quark (stop) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 inverse femtobarns of proton-proton collision data at sqrt(s) = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the stop mass below 360 to 410 GeV, depending on the higgsino mass

Severe early onset preeclampsia: short and long term clinical, psychosocial and biochemical aspects

Preeclampsia is a pregnancy specific disorder commonly defined as de novo hypertension and proteinuria after 20 weeks gestational age. It occurs in approximately 3-5% of pregnancies and it is still a major cause of both foetal and maternal morbidity and mortality worldwide1. As extensive research has not yet elucidated the aetiology of preeclampsia, there are no rational preventive or therapeutic interventions available. The only rational treatment is delivery, which benefits the mother but is not in the interest of the foetus, if remote from term. Early onset preeclampsia (<32 weeks’ gestational age) occurs in less than 1% of pregnancies. It is, however often associated with maternal morbidity as the risk of progression to severe maternal disease is inversely related with gestational age at onset2. Resulting prematurity is therefore the main cause of neonatal mortality and morbidity in patients with severe preeclampsia3. Although the discussion is ongoing, perinatal survival is suggested to be increased in patients with preterm preeclampsia by expectant, non-interventional management. This temporising treatment option to lengthen pregnancy includes the use of antihypertensive medication to control hypertension, magnesium sulphate to prevent eclampsia and corticosteroids to enhance foetal lung maturity4. With optimal maternal haemodynamic status and reassuring foetal condition this results on average in an extension of 2 weeks. Prolongation of these pregnancies is a great challenge for clinicians to balance between potential maternal risks on one the eve hand and possible foetal benefits on the other. Clinical controversies regarding prolongation of preterm preeclamptic pregnancies still exist – also taking into account that preeclampsia is the leading cause of maternal mortality in the Netherlands5 - a debate which is even more pronounced in very preterm pregnancies with questionable foetal viability6-9. Do maternal risks of prolongation of these very early pregnancies outweigh the chances of neonatal survival? Counselling of women with very early onset preeclampsia not only comprises of knowledge of the outcome of those particular pregnancies, but also knowledge of outcomes of future pregnancies of these women is of major clinical importance. This thesis opens with a review of the literature on identifiable risk factors of preeclampsia