1,618 research outputs found
Ageing and relaxation times in disordered insulators
We focus on the slow relaxations observed in the conductance of disordered
insulators at low temperature (especially granular aluminum films). They
manifest themselves as a temporal logarithmic decrease of the conductance after
a quench from high temperatures and the concomitant appearance of a field
effect anomaly centered on the gate voltage maintained. We are first interested
in ageing effects, i.e. the age dependence of the dynamical properties of the
system. We stress that the formation of a second field effect anomaly at a
different gate voltage is not a "history free" logarithmic (lnt) process, but
departs from lnt in a way which encodes the system's age. The apparent
relaxation time distribution extracted from the observed relaxations is thus
not "constant" but evolves with time. We discuss what defines the age of the
system and what external perturbation out of equilibrium does or does not
rejuvenate it. We further discuss the problem of relaxation times and comment
on the commonly used "two dip" experimental protocol aimed at extracting
"characteristic times" for the glassy systems (granular aluminum, doped indium
oxide...). We show that it is inoperable for systems like granular Al and
probably highly doped InOx where it provides a trivial value only determined by
the experimental protocol. But in cases where different values are obtained
like in lightly doped InOx or some ultra thin metal films, potentially
interesting information can be obtained, possibly about the "short time"
dynamics of the different systems. Present ideas about the effect of doping on
the glassiness of disordered insulators may also have to be reconsidered.Comment: to appear in the proceedings of the 14th International Conference on
Transport and Interactions in Disordered Systems (TIDS14
Assessment techniques, database design and software facilities for thermodynamics and diffusion
The purpose of this article is to give a set of recommendations to producers of assessed thermodynamic data, who may be involved in either the critical evaluation of limited chemical systems or the creation and dissemination of larger thermodynamic databases. Also, it is hoped that reviewers and editors of scientific publications in this field will find some of the information useful. Good practice in the assessment process is essential, particularly as datasets from many different sources may be combined together into a single database. With this in mind, we highlight some problems that can arise during the assessment process and we propose a quality assurance procedure. It is worth mentioning at this point, that the provision of reliable assessed thermodynamic data relies heavily on the availability of high quality experimental information. The different software packages for thermodynamics and diffusion are described here only briefly
Uses and Perceptions of the Neighborhood Open Space
This research investigates the uses and perceptions of the population of the East Carrollton Area in New Orleans so as to evaluate the possible outcomes of urban design intervention and policy changes. Using GIS, field notes, structured interviews and a population survey, this research evaluates how much the built environment influences the uses of the neighborhood open space. Subsequently, it evaluates how the neighborhood open space is perceived as a place as opposed to a transportation infrastructure.
Overall, the built environment affects the experience of the residents when they perform leisure activities in the neighborhood open space. Major deterrents to functional use and active transportation are related to social factors and the social environment. The neighborhood open space is largely perceived as an asset by the residents. It can be a valid replacement for urban parks when the population cannot access them
Uses and Perceptions of the Neighborhood Open Space
This research investigates the uses and perceptions of the population of the East Carrollton Area in New Orleans so as to evaluate the possible outcomes of urban design intervention and policy changes. Using GIS, field notes, structured interviews and a population survey, this research evaluates how much the built environment influences the uses of the neighborhood open space. Subsequently, it evaluates how the neighborhood open space is perceived as a place as opposed to a transportation infrastructure.
Overall, the built environment affects the experience of the residents when they perform leisure activities in the neighborhood open space. Major deterrents to functional use and active transportation are related to social factors and the social environment. The neighborhood open space is largely perceived as an asset by the residents. It can be a valid replacement for urban parks when the population cannot access them
Metocean conditions at two Norwegian sites for development of offshore wind farms
This paper examines metocean data from NORA3, a state-of-the-art wind and wave hindcast dataset for Northern Europe. Two offshore Norwegian areas, Utsira Nord (UN) and Sørlige Nordsjø II (SN2), are investigated. Both areas offer significant potential for the offshore wind sector. UN is situated in deep-sea water, suitable for floating offshore wind turbines. In contrast, SN2 lies in intermediate waters and ranks among the North Sea's most promising regions allocated for offshore wind. Data from NORA3, originally on a 3-km resolution grid, are resampled into unstructured grids spanning from 1982 to 2022. This refined dataset offers a climatology time scale with superior spatial and temporal resolution compared to most other hindcast and reanalysis databases. The study examines mean wind speed and direction across seven levels, ranging from 10~m to 750~m above the surface. Analyses of extreme wind and wave conditions have been conducted. Results reveal that UN experiences higher extreme wave heights than SN2 while the extreme wind speeds may be substantially larger at SN2 than UN. Moreover, this study establishes joint distribution models that encompass several parameters, including mean wind speed, significant wave height, wave spectral peak period, and direction difference between wind and waves. Thus, this metocean data is valuable for designing and analyzing floating wind farms over their lifecycles.publishedVersio
Identification of the hASCT2-binding domain of the Env ERVWE1/syncytin-1 fusogenic glycoprotein
The cellular HERV-W envelope/syncytin-1 protein, encoded by the envelope gene of the ERVWE1 proviral locus is a fusogenic glycoprotein probably involved in the formation of the placental syncytiotrophoblast layer. Syncytin-1-induced in vitro cell-cell fusion is dependent on the interaction with hASCT2. As no receptor binding domain has been clearly defined in the SU of neither the HERV-W Env nor the retroviruses of the same interference group, we designed an in vitro binding assay to evaluate the interaction of the HERV-W envelope with the hASCT2 receptor. Using truncated HERV-W SU subunits, a region consisting of the N-terminal 124 amino acids of the mature SU glycoprotein was determined as the minimal receptor-binding domain. This domain contains several sub-domains which are poorly conserved among retroviruses of this interference group but a region of 18 residus containing the SDGGGX(2)DX(2)R conserved motif was proved to be essential for syncytin-1-hASCT2 interaction
Velocity spectra and coherence estimates in the marine atmospheric boundary layer
Two years of continuous sonic anemometer measurements conducted in 2007 and 2008 at the FINO1 platform are used to investigate the characteristics of the single- and two-point velocity spectra in relation to the atmospheric stability in the marine atmospheric boundary layer. The goals are to reveal the limits of current turbulence models for the estimation of wind loads on offshore structures, and to propose a refined description of turbulence at altitudes where Monin–Obukhov similarity theory may be limited. Using local similarity theory, a composite spectrum model, combining a pointed and a blunt model, is proposed to describe the turbulence spectrum for unstable, neutral and stable conditions. Such a model captures the −1 power law followed by the velocity spectra at an intermediate frequency range in the marine atmospheric boundary layer. For the Monin–Obukhov similarity parameter ζ<0.3, the Davenport coherence model captures the vertical coherence of the horizontal velocity components well. A two-parameter exponential decay function is found more appropriate for modelling the coherence of the vertical velocity component. Under increasingly stable conditions, the size of the eddies in the vertical coordinate reduces, such that smaller separation distances than that covered in the present dataset may be required to study the coherence with sufficient accuracy.acceptedVersio
Valérie Guyen-Croquez, Tradition et Originalité dans les Croniques et Conquestes de Charlemaine de David Aubert
L’ouvrage de Valérie Guyen-Croquez est issu de sa thèse de doctorat soutenue à l’université de Lorraine en 2008 sous la direction de Bernard Guidot. C’est une monographie consacrée aux Croniques et Conquestes de Charlemaine, vaste compilation en prose rédigée avant 1458 par l’escripvain David Aubert à la gloire du grand empereur, qui mêle dérimages de chansons de geste et réécriture de chroniques. Composé de cinq parties, l’ouvrage complète l’étude littéraire par un pan linguistique (quatrièm..
Magali Cheynet, « Joindre le chief avecques les membres. » Remembrer et compiler l’histoire de Charlemagne dans la deuxième moitié du xve siècle,
Dans la deuxième moitié du xve siècle, plusieurs compilations rassemblent et remanient en prose les récits associés à Charlemagne : c’est le cas des Croniques et conquestes de Charlemaine de David Aubert (vers 1458), de l’Histoire de Charlemagne de Jean Bagnyon (aussi connue sous le titre de Fierabras en prose, avant 1478) et de l’anonyme Cronique associee de Charlemaine tres louable et Anseïs icy couplee (= CA ; avant 1484). Composées dans des milieux différents à un moment où tant la réécri..
La route des pèlerins : introduction
« Au commencement était la route », écrivait Joseph Bédier pour expliquer l’origine et la formation des chansons de geste, qu’il supposait avoir été transmises le long des grandes routes de pèlerinage. Il ne s’agit pas ici de revenir sur ce débat ancien, mais de mettre la route des pèlerins au cœur de notre réflexion : parler de l’origine des routes plutôt que de l’origine des textes, partir de la route pour comprendre la démarche des pèlerins et appréhender leur expérience quotidienne du voy..
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