Aeshna vercanica sp. nov. from Iran with a new insight into the Aeshna cyanea-group (Odonata: Aeshnidae)

Aeshna vercanica sp. nov. is described and illustrated. The male holotype and four male paratypes were collected on 15-vii-2013 in the Hyrcanian forest of the Alborz Mountains, Mazandaran province, northwestern Iran. A specimen collected on 29-vi-2002 in the Talysh Hills, Lankoran area, Azerbaijan, also belongs to the new species. In July 2014 the species, including females, was recorded again at the type locality and additionally ca 400 km further east in Golestan province. Males are similar to Aeshna cyanea in the structure of genitalia and terminalia but differ in head morphology, pterostigma length, colour pattern, and behaviour. Females have small abdominal blue or turquoise postero-median dorsal spots which are absent on S9 and S10, thin green antehumeral stripes, a less robust appearance than females of A. cyanea, and are more slender and longer. The range of A. vercanica sp. nov. covers the Hyrcanian forest along the southern margin of the Caspian Sea. Analysis of the barcoding COI sequence of DNA confirmed that A. vercanica sp. nov. is separated from A. cyanea by a genetic distance of ca 4%. The ITS gave a similar result. A haplotype map could not derive A. vercanica sp. nov. directly from A. cyanea. They are thus related but different species, and we suggest the common ancestor lived in pre-Pleistocene times. Analysis of A. cyanea specimens from across its range also revealed a western clade from the Maghreb to Central Europe. Populations from the Caucasus to Eastern Europe were polytomous, a common scenario for post-glacial invaders. A molecular comparison of the species pair A. juncea and A. subarctica showed these to be even more closely related than A. cyanea and A. vercanica sp. nov

Waveform relaxation methods for stochastic differential equations

An operator equation X = Π X + G in a Banach space 퓔 of 퓕t-adapted random elements describing an initial- or boundary value problem of a system of stochastic differential equations (SDEs) is considered. Our basic assumption is that the underlying system consists of weakly coupled subsystems. The proof of the convergence of corresponding waveform relaxation methods depends on the property that the spectral radius of an associated matrix is less than one. The entries of this matrix depend on the Lipschitz-constants of a decomposition of Π. In proving an existence result for the operator equation we show how the entries of the matrix depend on the right hand side of the stochastic differential equations. We derive conditions for the convergence under "classical" vector-valued Lipschitz-continuity of an appropriate splitting of the system of stochastic ODEs. A generalization of these key results under one-sided Lipschitz continuous and anticoercive drift coefficients of SDEs is also presented. Finally, we consider a system of SDEs with different time scales (singularly perturbed SDEs) as an illustrative example

Waveform relaxation methods for stochastic differential equations

An operator equation X = Π X + G in a Banach space 퓔 of 퓕t-adapted random elements describing an initial- or boundary value problem of a system of stochastic differential equations (SDEs) is considered. Our basic assumption is that the underlying system consists of weakly coupled subsystems. The proof of the convergence of corresponding waveform relaxation methods depends on the property that the spectral radius of an associated matrix is less than one. The entries of this matrix depend on the Lipschitz-constants of a decomposition of Π. In proving an existence result for the operator equation we show how the entries of the matrix depend on the right hand side of the stochastic differential equations. We derive conditions for the convergence under "classical" vector-valued Lipschitz-continuity of an appropriate splitting of the system of stochastic ODEs. A generalization of these key results under one-sided Lipschitz continuous and anticoercive drift coefficients of SDEs is also presented. Finally, we consider a system of SDEs with different time scales (singularly perturbed SDEs) as an illustrative example

An assessment of contact metallization for high power and high temperature diamond Schottky devices

Different metals W, Al, Ni and Cr were evaluated as Schottky contacts on the same p-type lightly boron doped homoepitaxial diamond layer. The current–voltage (I–V) characteristics, the series resistance and the thermal stability are discussed in the range of RT to 625 K for all Schottky devices. High current densities close to 3.2 kA/cm2 are displayed and as the series resistance decreases with increasing temperature, proving the potential of diamond for high power and high temperature devices. The thermal stability of metal/diamond interface investigated with regards to the Schottky barrier height (SBH) and ideality factor n fluctuations indicated that Ni and W are thermally stable in the range of RT to 625 K. Current–voltage measurements at reverse bias indicated a maximum breakdown voltage of 70 V corresponding to an electric field of 3.75 MV/cm. Finally, these electrical measurements have been completed with mechanical adhesion tests of contact metallizations on diamond by nano-scratching technique. These studies clearly reveal Ni as a promising contact metallization for high power, high temperature and good mechanical strength diamond Schottky barrier diode applications

Gestion thermique des composants d'électronique de puissance - Utilisation du diamant CVD

L'augmentation de la densité de puissance des convertisseurs d'énergie électrique nécessite une gestion thermique toujours plus performante. La thermique devient même l'élément dimensionnant de ces convertisseurs et est au centre des préoccupations des concepteurs. Le diamant présente des propriétés physico-chimiques exceptionnelles particulièrement adaptées à la gestion thermique des composants semi-conducteurs de l'électronique de puissance. C'est en effet le meilleur matériau isolant et conducteur thermique connu à ce jour. La possibilité de réaliser du diamant polycristallin de manière reproductible par synthèse CVD ouvre aujourd'hui à ce matériau un grand champ d'applications industrielles. Nous avons étudié les potentialités d'applications au domaine particulier de l'électronique de puissance. Nous avons tout d'abord développé une plateforme de simulation COMSOL qui nous permette d'évaluer différentes structures pour optimiser le système de refroidissement des composants d'électronique de puissance. Nous avons alors étudié deux solutions, l'utilisation d'un substrat diamant épais pour reporter les composants ou le dépôt direct d'une fine couche de passivation sur les composants en fin de fabrication. Nous avons ainsi développé une structure à substrat diamant et micropoteaux en cuivre qui permet d'extraire jusqu'à 800 W/cm sous le composant pour un échauffement de 120C. Cette structure a été réalisée technologiquement pour valider toute la démarche de simulation et conception. Ce prototype propose des performances particulièrement intéressantes pour l'intégration des convertisseurs d'électronique de puissance à haute densité de puissance. Nous avons également étudié la passivation des composants avec du diamant CVD en lieu et place du SiO2. L'intérêt d'une telle passivation est démontré en simulation et les différentes étapes de la réalisation technologique sont étudiées. Cette dernière partie met en évidence des difficultés qu'il faudra lever si l'on souhaite utiliser le diamant comme couche de passivationThe heat transfer is a major obstacle that limits the generalization of the power electronics. During recent years, components have higher performance and smaller size thanks to technological advances in electronic. However, the maximum operation temperature of silicon components has not changed for years. A lot of problems will appear due to the thermal limitation. Thus, electronic circuit design must be accompanied by a thermal study to validate the safe operation. The diamond has outstanding properties. It has several exceptional physical and chemical characteristics. This material is very interesting in plenty of application domains, such as electronics, mechanics, optics and telecommunications. This is the best material for electrical insulators (10MV.cm-1) and thermal conductors (2000W.m-1.K-1, five times more than copper). Nevertheless, the coefficient of thermal expansion of diamond is very close to that of silicon. These properties are particularly interesting in elaborating highly efficient thermal management systems in power electronics domain. In this study, we analyzed and quantified the advantages of the insertion of CVD diamond layer in the innovative thermal management assemblies. We also developed a specific model (We increased a layer of copper micro-pillars on the backside of the diamond substrate) to simulate the working environment of the component. In the simulation, we compared the use of a traditional substrate (AlN) with that of the diamond CVD one in order to confirm that using the diamond substrate reduced thermal resistance. By using MEMS micro-technology, the cooling performance of this structure has been greatly improved. This structure can achieve power dissipation more than 800W/cm . Using CVD diamond for efficient cooling of power devices could be a promising solution and is very interesting in embedded systems. This achievement in temperature range allows designers to increase the power density of system without concerning of heat dissipation and/or greatly extends the lifetime of the device. We also studied the passivation with CVD diamond instead of SiO2TOULOUSE-INP (315552154) / SudocSudocFranceF

Positronium chemistry studied by AMOC measurements using a relativistic positron beam

Beam-based Age-Momentum Correlation (β+γΔE AMOC) measurements using an MeV positron beam have become a powerful tool to study chemical reactions of positronium by time-domain observations of the different positron states tagged by the Doppler-broadening (ΔE) characteristics of the 511 keV annihilation radiation. As an example, the investigation of the spin-conversion reaction in the system HTEMPO/methanol is reported. The experimental data for small HTEMPO concentrations can be fitted quite well to a rate-equation model containing the conversion rate as the only adjustable parameter. This model can presumably be applied not only to spin conversion but also to other chemical reactions and to inhibition of positronium. Possible effects of oxidation, complex formation, and inhibition are discussed by way of examples

AXES at TRECVid 2011

The AXES project participated in the interactive known-item search task (KIS) and the interactive instance search task (INS) for TRECVid 2011. We used the same system architecture and a nearly identical user interface for both the KIS and INS tasks. Both systems made use of text search on ASR, visual concept detectors, and visual similarity search. The user experiments were carried out with media professionals and media students at the Netherlands Institute for Sound and Vision, with media professionals performing the KIS task and media students participating in the INS task. This paper describes the results and findings of our experiments

IR Spectrum of the O-H......O Hydrogen Bond of Phthalic Acid Monomethylester in Gas Phase and in CCl4_4 Solution

The absorption spectrum of the title compound in the spectral range of the Hydrogen-bonded OH-stretching vibration has been investigated using a five-dimensional gas phase model as well as a QM/MM classical molecular dynamics simulation in solution. The gas phase model predicts a Fermi-resonance between the OH-stretching fundamental and the first OH-bending overtone transition with considerable oscillator strength redistribution. The anharmonic coupling to a low-frequency vibration of the Hydrogen bond leading to a vibrational progression is studied within a diabatic potential energy curve model. The condensed phase simulation of the dipole-dipole correlation function results in a broad band in the 3000 \cm region in good agreement with experimental data. Further, weaker absorption features around 2600 \cm have been identified as being due to motion of the Hydrogen within the Hydrogen bond.Comment: Contribution to Horizons in Hydrogen Bond Research Conference, Paris 200

A new ordering parameter of spectral energy distributions from synchrotron-self-Compton emitting blazars

The broadband SEDs of blazars exhibit two broad spectral components, which in leptonic emission models are attributed to synchrotron radiation and synchrotron self-Compton (SSC) radiation of relativistic electrons. During high state phases, the high-frequency SSC component often dominates the low-frequency synchrotron component, implying that the inverse Compton SSC losses of electrons are at least equal to or greater than the synchrotron losses of electrons. We calculate from the analytical solution of the kinetic equation of relativistic electrons, subject to the combined linear synchrotron and nonlinear synchrotron self-Compton cooling, for monoenergetic injection the time-integrated total synchrotron and SSC radiation fluences and spectral energy distributions (SED). Depending on the ratio of the initial cooling terms, displayed by the injection parameter $\alpha$, we find for $\alpha\ll 1$, implying complete linear cooling, that the synchrotron peak dominates the inverse Compton peak and the usual results of the spectra are recovered. For $\alpha\gg 1$ the SSC peak dominates the synchrotron peak, proving our assumption that in such a case the cooling becomes initially non-linear. The spectra also show some unique features, which can be attributed directly to the non-linear cooling. To show the potential of the model, we apply it to outbursts of 3C 279 and 3C 454.3, successfully reproducing the SEDs. The results of our analysis are promising, and we argue that this non-equilibrium model should be considered in future modeling attempts for blazar flares.Comment: accepted by MNRAS, 32 pages (single column), 7 figure

Plas'O'Soins: a software platform for modeling, planning and monitoring homecare activities

International audienceDemographic changes in recent years have contributed to a shift in care models, with the development of homecare as a new alternative to traditional hospitalization. We present a software platform dedicated to the modeling, planning and monitoring of homecare workflows, developed in the framework of the French research program TecSan. The platform is used on the desktop by care coordinators, and on the go by care workers using mobile devices