Search results for "NEA"
showing 10 items of 16082 documents
Design criteria of tubular linear induction motors and generators: A prototype realization and its characterization
2013
In this paper a mathematical model of tubular linear induction machines (TLIM) with hollowed induced part is recalled. Moreover the design criteria of a TLIM with hollowed iron induced part are presented as well as the technological processes to be adopted and the choice of materials to construct the various parts. The methodologies for mechanical assembling and electric wiring are considered too. A prototype with bimetallic induced part has been designed and built. Finally some experimental results on electrical and mechanical variables, when the machines are used as motors, are shown.
La métallurgie du fer au Sahel : Répartition spatiale de bas fourneaux au Sud-Ouest du Niger. Premiers résultats
2010
International audience; A 15 km à l'Est de Niamey (Sud-Ouest du Niger), une prospection pédestre exhaustive a permis de dénombrer plus de 4000 bas-fourneaux sur un bassin versant de 24 km². Ils sont identifiables par la présence de scories correspondant aux résidus de réduction du fer. Ce grand nombre de structures de réduction est lié au fonctionnement à usage unique des bas-fourneaux, qui est peu étudié dans la région ouest africaine. Les premières études de répartition spatiale montrent que l'implantation de ces bas-fourneaux est principalement soumise à la géomorphologie. Les forgerons ont installé leurs sites de réduction à proximité des talus de plateaux où affleure le minerai de fer …
Posada en valor de la pintura mural gòtica lineal a territori valencià. Un cas a descobrir: el Palau-Castell de Llutxent
2016
Solid-state-biased coherent detection of ultra-broadband terahertz pulses
2017
Significant progress in nonlinear and ultrafast optics has recently opened new and exciting opportunities for terahertz (THz) science and technology, which require the development of reliable THz sources, detectors, and supporting devices. In this work, we demonstrate the first solid-state technique for the coherent detection of ultra-broadband THz pulses (0.1-10 THz), relying on the electric-field-induced second-harmonic generation in a thin layer of ultraviolet fused silica. The proposed CMOS-compatible devices, which can be realized with standard microfabrication techniques, allow us to perform ultra-broadband detection with a high dynamic range by employing probe laser powers and bias v…
The role of Mediterranean wetlands in climate regulation and greenhouse gases exchanges: from carbon biogeochemistry to European water and nature Dir…
2022
Atesa la seua alta activitat biogeoquímica, els aiguamolls són un dels tipus d'ecosistemes més actius en el cicle global del carboni, amb altes taxes d'intercanvi de carboni i de gasos d'efecte hivernacle (GEH), i, per tant, un gran potencial de regulació climàtica. Una de les parts més importants de la biogeoquímica del carboni als aiguamolls està lligada a les taxes metabòliques, a partir del coneixement de les quals es pot determinar un balanç de carboni associat amb el potencial intercanvi de carboni amb l'atmosfera. La seua capacitat per retindre carboni i mitigar el canvi climàtic, o, per contra, d'alliberar més GEH, i contribuir a l'escalfament global, es determina pel balanç de carb…
Experimental investigations of backward transition radiation characteristics in extreme ultraviolet region
2011
ABSTRACT This report summarizes the results of an experiment dedicated to the observation of backward transition radia-tion in the EUV spectral region. This radiation was ge nerated by an 855MeV electron beam at a molybdenumtarget. The radiation characteristics in the EUV region are compared to those in the optical region. It wasshown that the radiation measured in the EUV region was more intense than theoretically predicted. As aresult the EUV radiation yield seems to be suci ent for standard beam prole diagnostics.Keywords: EUV, Transition radiation, Beam diagnostics 1. INTRODUCTION Transverse prole diagnostics in mo dern electron linear accelerators as F ELs or injector linacs is mainl…
2015
Songs in passerine birds are important for territory defense and mating. Speciation rates in oscine passerines are so high, due to cultural evolution, that this bird lineage makes up half of the extant bird species. Leaf warblers are a speciose Old-World passerine family of limited morphological differentiation, so that songs are even more important for species delimitation. We took 16 sonographic traits from song recordings of 80 leaf warbler taxa and correlated them with 15 potentially explanatory variables, pairwise, and in linear models. Based on a well-resolved molecular phylogeny of the same taxa, all pairwise correlations were corrected for relatedness with phylogenetically independe…
Monte Carlo simulation of many-arm star polymers in two-dimensional good solvents in the bulk and at a surface
1991
A Monte Carlo technique is proposed for the simulation of statistical properties of many-arm star polymers on lattices. In this vectorizing algorithm, the length of each arml is increased by one, step by step, from a starting configuration withl=1 orl=2 which is generated directly. This procedure is carried out for a large sample (e.g., 100,000 configurations). As an application, we have studied self-avoiding stars on the square lattice with arm lengths up tol max=125 and up tof=20 arms, both in the bulk and in the geometry where the center of the star is adsorbed on a repulsive surface. The total number of configurations, which behaves asN∼l γ G–1μ fl , whereμ=2.6386 is the usual effective…
In Situ Heating TEM Study of Onion-like WS2 and MoS2 Nanostructures Obtained via MOCVD
2007
We report on the in situ heating transmission electron microscopy (TEM) study of WS2 and MoS2 nanoparticles obtained from metal–organic chemical vapor deposition (MOCVD). The general behavior of MoS2 and WS2 is similar: Round, amorphous particles in the pristine sample transform to hollow, onion-like particles upon annealing. A second type of particle with straight layers exhibits only minor changes. A significant difference between both compounds could be demonstrated in their crystallization behavior. The results of the in situ heating experiments are compared to those obtained from an ex situ annealing process under Ar.
Análisis tiempo-frecuencia de la fibrilación ventricular. Estudio experimental
2006
Introduction and objectives. The analysis of frequency variability during ventricular fibrillation has yielded inconsistent results. We used an experimental model of ventricular fibrillation, with a short timescale, to analyze variations in frequency and their associated spatial distribution. Methods. Epicardial recordings of ventricular fibrillation were made in 10 perfused isolated rabbit heart preparations using a multiple electrode system (i.e., 240 unipolar electrodes). Both spectral and time-frequency analysis were used to derive the dominant frequency in the anterolateral wall of the left ventricle. Results. Linear regression analysis showed that there was a good correlation between …