1,119 research outputs found
Velocity of sound in a Bose-Einstein condensate in the presence of an optical lattice and transverse confinement
We study the effect of the transverse degrees of freedom on the velocity of
sound in a Bose-Einstein condensate immersed in a one-dimensional optical
lattice and radially confined by a harmonic trap. We compare the results of
full three-dimensional calculations with those of an effective 1D model based
on the equation of state of the condensate. The perfect agreement between the
two approaches is demonstrated for several optical lattice depths and
throughout the full crossover from the 1D mean-field to the Thomas Fermi regime
in the radial direction.Comment: final versio
Parallel and Context Based Search in Cloud using Multi Agent System
Cloud Computing is one of the fast growing Technology. Cloud computing support large scale infrastructure used to increase high performance of computing. This technology support agents and with the help of integration of the agents that is Multi Agent System (MAS) which is capable of intelligent behavior. They run in an environment where they communicate with each other using message passing technique. Each agent has its own set of behavior and they run independent of each other. When a message arrives each agent shows their own behavior and hence an agent shows their coordination. The use of MAS in cloud computing help us for searching context with better performance. The JADE is a platform which supports agent. This paper discusses about Cloud computing models and architectures, information retrieving technique and the use of MAS that improve the performance of big data search from Distributed File System (DFS) which is difficult to achieve using single agent or thread. Keywords: Cloud Computing, Distributed File System, JADE, MA
Recommended from our members
Killed in action (KIA): an analysis of military personnel who died of their injuries before reaching a definitive medical treatment facility in Afghanistan (2004-2014).
INTRODUCTION: The majority of combat deaths occur before arrival at a medical treatment facility but no previous studies have comprehensively examined this phase of care. METHODS: The UK Joint Theatre Trauma Registry was used to identify all UK military personnel who died in Afghanistan (2004-2014). These data were linked to non-medical tactical and operational records to provide an accurate timeline of events. Cause of death was determined from records taken at postmortem review. The primary objective was to report time between injury and death in those killed in action (KIA); secondary objectives included: reporting mortality at key North Atlantic Treaty Organisation timelines (0, 10, 60, 120 min), comparison of temporal lethality for different anatomical injuries and analysing trends in the case fatality rate (CFR). RESULTS: 2413 UK personnel were injured in Afghanistan from 2004 to 2014; 448 died, with a CFR of 18.6%. 390 (87.1%) of these died prehospital (n=348 KIA, n=42 killed non-enemy action). Complete data were available for n=303 (87.1%) KIA: median Injury Severity Score 75.0 (IQR 55.5-75.0). The predominant mechanisms were improvised explosive device (n=166, 54.8%) and gunshot wound (n=96, 31.7%).In the KIA cohort, the median time to death was 0.0 (IQR 0.0-21.8) min; 173 (57.1%) died immediately (0 min). At 10, 60 and 120 min post injury, 205 (67.7%), 277 (91.4%) and 300 (99.0%) casualties were dead, respectively. Whole body primary injury had the fastest mortality. Overall prehospital CFR improved throughout the period while in-hospital CFR remained constant. CONCLUSION: Over two-thirds of KIA deaths occurred within 10 min of injury. Improvement in the CFR in Afghanistan was predominantly in the prehospital phase
Microbiological aspects of methane emission in a ricefield soil from the Camargue (France) : 2. Methanotrophy and related microflora
Les principaux facteurs qui influencent l'activité méthanotrophe du sol (épaisseur du sol, humidité, addition d'engrais et dessiccation) ont été étudiés in vitro sur un sol de rizière de Camargue (France) afin de standardiser une méthode pour estimer l'activité méthanotrophe potentielle (PMA) d'un sol. La possibilité d'énumérer les méthanotrophes du sol a été étudiée et les souches dominantes du sol incubé pendant un mois sous un mélange de 80% air/20% CH4 ont été isolées. La méthanotrophie in vitro est un phénomène quantifiable par unité de surface plutôt que par unité de poids de sol. L'activité maximale (PMA)(1.8 mole m-2 j-1) a été mesurée sur un échantillon à une humidité voisine de la capacité au champ et incubé pendant un mois sous air/CH4. Les consommations de CH4 et d'O2 ainsi que la production de CO2 sont fortement corrélées. La consommation d'O2 liée à l'activité hétérotrophe du sol est négligeable comparée à celle due à l'activité méthanotrophe. L'addition d'engrais à des concentrations utilisées en agriculture est sans effet sur la PMA qui est restée stable pendant deux ans dans le sol conservé à l'état sec. Une très forte contamination rend les étalements sur boites de Pétri inexploitables pour dénombrer les bactéries méthanotrophes du sol. Les populations estimées par MPN sont faibles dans le sol sec (2.5 x 102 g-1) et atteignent 5 x 108 g-1 dans le sol enrichi. La morphologie des souches isolées indique leur appartenance aux bactéries méthanotrophes de type II. (Résumé d'auteur
On Vertex-Centered Unstructured Finite-Volume Methods for Stretched Anisotropic Triangulations
Vertex-Centered Finite-Volume schemes applied to triangulations may present poor accuracy when stretched meshes are used. We introduce a family of variational schemes with three parameters for each triangle and investigate the conditions these parameters must meet in order to have a good behavior on stretched meshes. Some of the resulting schemes are also more qualified for computations on quasi-cartesian meshes than standard schemes with cells limited by medians. We obtain among others the Barth finite volume scheme. These schemes are also related to the so-called MDHR schemes. Application to transonic flows around cylinders and in a booster combustion chamber are discussed
Electronic and physico-chemical properties of nanmetric boron delta-doped diamond structures
Heavily boron doped diamond epilayers with thicknesses ranging from 40 to less than 2 nm and buried between nominally undoped thicker layers have been grown in two different reactors. Two types of [100]-oriented single crystal diamond substrates were used after being characterized by X-ray white beam topography. The chemical composition and thickness of these so-called deltadoped structures have been studied by secondary ion mass spectrometry, transmission electron microscopy, and spectroscopic ellipsometry. Temperature-dependent Hall effect and four probe
resistivity measurements have been performed on mesa-patterned Hall bars. The temperature dependence of the hole sheet carrier density and mobility has been investigated over a broad temperature range (6K<T<450 K). Depending on the sample, metallic or non-metallic behavior was observed. A hopping conduction mechanism with an anomalous hopping exponent was detected in the non-metallic samples. All metallic delta-doped layers exhibited the same mobility value, around 3.660.8 cm2/Vs, independently of the layer thickness and the substrate type. Comparison with previously published data and theoretical calculations showed that scattering by ionized impurities explained only partially this low common value. None of the delta-layers showed any sign of confinement-induced mobility enhancement, even for thicknesses lower than 2 nm.14 page
Superfluid to Mott insulator transition in one, two, and three dimensions
We have created one-, two-, and three-dimensional quantum gases and study the
superfluid to Mott insulator transition. Measurements of the transition using
Bragg spectroscopy show that the excitation spectra of the low-dimensional
superfluids differ significantly from the three-dimensional case
- …