430 research outputs found

    La couleur des sols : appréciation, mesure et relations avec les propriétés spectrales

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    La couleur est une donnée de sol très utilisée, aussi bien dans les travaux de terrain que dans les systèmes de classifications. Son étude se développe actuellement en relation avec les propriétés spectrales des sols et de leurs constituants, observées au laboratoire ou par télédétection. Dans cet article, des éléments de colorimétrie sont rappelés, puis appliqués à une série de 84 échantillons de sols très diversifiés. La mise en évidence de la fréquence négligeable du métamérisme permet de modéliser les relations entre couleur et propriétés spectrales qui en sont à l'origine. Grâce à ce résultat, les couleurs de sol notées sur le terrain à l'aide du code Munsell prennent une signification physique, permettant d'aborder leur interprétation sous un jour nouveau. (Résumé d'auteur

    Modeling the relationships between Munsell soil color and soil spectral properties

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    Référentiel pédologique 2008

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    Le RĂ©fĂ©rentiel pĂ©dologique est un système de dĂ©signation des sols.C’est une typologie pĂ©dologique dĂ©taillĂ©e, parfaitement adaptĂ©e Ă  la multiplicitĂ© des sols prĂ©sents sur notre territoire, mais aussi Ă  de très nombreux sols observĂ©s en Europe, en Afrique et sur les autres continents. Le RĂ©fĂ©rentiel pĂ©dologique est le seul système officiel de dĂ©signationdes sols reconnu par les diffĂ©rents ministères dans le cadre des principaux programmes nationaux d’inventaire (IGCS) et de suivi des sols. Par ailleurs, il sert de rĂ©fĂ©rence explicite pour la dĂ©finition des « zones humides » (Meeddat – arrĂŞtĂ© du 24 juin 2008). Entièrement remaniĂ© et très fortement augmentĂ©, ce nouveau millĂ©sime du RĂ©fĂ©rentiel pĂ©dologique s’est enrichi de trois nouveaux chapitrestraitant de solums des zones intertropicales et de leurs horizons de rĂ©fĂ©rence spĂ©cifiques, ainsi que de deux outils inĂ©dits : une clĂ© d’accès rapide aux diffĂ©rents chapitres et une annexe des correspondances possibles entre les rĂ©fĂ©rences du RĂ©fĂ©rentiel pĂ©dologique et les catĂ©gories de la World Reference Base for soil resources. Ă€ l’Ă©preuve du terrain depuis plus de quinze ans, le RĂ©fĂ©rentielpĂ©dologique est dĂ©sormais incontournable. Conçu pour ĂŞtre accessibleaux non-spĂ©cialistes qui maĂ®trisent le vocabulaire de base de la pĂ©dologie, il est indispensable Ă  tous ceux qui doivent prendre en compte la diversitĂ© des sols

    Haloperidol and Ziprasidone for Treatment of Delirium in Critical Illness

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    BACKGROUND: There are conflicting data on the effects of antipsychotic medications on delirium in patients in the intensive care unit (ICU). METHODS: In a randomized, double-blind, placebo-controlled trial, we assigned patients with acute respiratory failure or shock and hypoactive or hyperactive delirium to receive intravenous boluses of haloperidol (maximum dose, 20 mg daily), ziprasidone (maximum dose, 40 mg daily), or placebo. The volume and dose of a trial drug or placebo was halved or doubled at 12-hour intervals on the basis of the presence or absence of delirium, as detected with the use of the Confusion Assessment Method for the ICU, and of side effects of the intervention. The primary end point was the number of days alive without delirium or coma during the 14-day intervention period. Secondary end points included 30-day and 90-day survival, time to freedom from mechanical ventilation, and time to ICU and hospital discharge. Safety end points included extrapyramidal symptoms and excessive sedation. RESULTS: Written informed consent was obtained from 1183 patients or their authorized representatives. Delirium developed in 566 patients (48%), of whom 89% had hypoactive delirium and 11% had hyperactive delirium. Of the 566 patients, 184 were randomly assigned to receive placebo, 192 to receive haloperidol, and 190 to receive ziprasidone. The median duration of exposure to a trial drug or placebo was 4 days (interquartile range, 3 to 7). The median number of days alive without delirium or coma was 8.5 (95% confidence interval [CI], 5.6 to 9.9) in the placebo group, 7.9 (95% CI, 4.4 to 9.6) in the haloperidol group, and 8.7 (95% CI, 5.9 to 10.0) in the ziprasidone group (P=0.26 for overall effect across trial groups). The use of haloperidol or ziprasidone, as compared with placebo, had no significant effect on the primary end point (odds ratios, 0.88 [95% CI, 0.64 to 1.21] and 1.04 [95% CI, 0.73 to 1.48], respectively). There were no significant between-group differences with respect to the secondary end points or the frequency of extrapyramidal symptoms. CONCLUSIONS: The use of haloperidol or ziprasidone, as compared with placebo, in patients with acute respiratory failure or shock and hypoactive or hyperactive delirium in the ICU did not significantly alter the duration of delirium. (Funded by the National Institutes of Health and the VA Geriatric Research Education and Clinical Center; MIND-USA ClinicalTrials.gov number, NCT01211522 .)

    Topological Defect Densities in Type-I Superconducting Phase Transitions

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    We examine the consequences of a cubic term addition to the mean-field potential of Ginzburg-Landau theory to describe first order superconductive phase transitions. Constraints on its existence are obtained from experiment, which are used to assess its impact on topological defect creation. We find no fundamental changes in either the Kibble-Zurek or Hindmarsh-Rajantie predictions.Comment: Revtex4, 1 eps figure, 6 pages. Change in title and in sections II and III so to broaden the scope of the paper. Additional author is include

    Synthesis and electrochemical behavior of ceramic cation-exchange membranes based on zirconium phosphate

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    Cation-exchange membranes made exclusively from ceramic materials have been synthesized by means of the impregnation of microporous ceramic supports with zirconium phosphate. Changes in the pore size distribution and total pore volume of the supports were provoked by the addition of starch as pore former in the fabrication procedure. This allowed the production of supports with increased effective electrical conductivities and with larger pores available for the zirconium phosphate deposition. An improved functionality for the exchange of cations was given to the ceramic membranes by means of their impregnation with the active particles of zirconium phosphate. The ion-exchange properties of the membranes were increased with further impregnation cycles and the resulting current voltage curves showed a similar shape to that typical of commercial polymeric ion-exchange membranes. The production of ionexchange membranes with increased chemical and radiation stability will broaden their applicability for the treatment of specific industrial waste waters, which are very aggressive for the current commercial ion-exchange membranes.Manuel-Cesar Marti-Calatayud wants to express his gratitude to Universitat Politecnica de Valencia for a postgraduate grant (Ref. 2010-12). S. Sales would like to express her gratitude to Ministerio de Ciencia e Investigacion (Spain) for a postgraduate grant (AP2009-4409). This work was supported by Ministerio de Ciencia e Innovacion (Spain) with the project numbers CTQ2008-06750-C02-01/PPQ and CTQ2008-06750-C02-02/PPQ.MartĂ­ Calatayud, MC.; GarcĂ­a GabaldĂłn, M.; PĂ©rez-Herranz, V.; Sales, S.; Mestre, S. (2013). Synthesis and electrochemical behavior of ceramic cation-exchange membranes based on zirconium phosphate. Ceramics International. 39(4):4045-4054. https://doi.org/10.1016/j.ceramint.2012.10.255S4045405439

    The ANTARES Optical Beacon System

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    ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular when a muon is produced, provided that the Cherenkov photons are detected with sufficient timing precision. Considerations of the intrinsic time uncertainties stemming from the transit time spread in the photomultiplier tubes and the mechanism of transmission of light in sea water lead to the conclusion that a relative time accuracy of the order of 0.5 ns is desirable. Accordingly, different time calibration systems have been developed for the ANTARES telescope. In this article, a system based on Optical Beacons, a set of external and well-controlled pulsed light sources located throughout the detector, is described. This calibration system takes into account the optical properties of sea water, which is used as the detection volume of the ANTARES telescope. The design, tests, construction and first results of the two types of beacons, LED and laser-based, are presented.Comment: 21 pages, 18 figures, submitted to Nucl. Instr. and Meth. Phys. Res.

    Effect of mandibular advancement therapy on inflammatory and metabolic biomarkers in patients with severe obstructive sleep apnoea: a randomised controlled trialTrial registration number

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    Systemic inflammation and metabolic disorders are among the mechanisms linking obstructive sleep apnoea (OSA) and cardiovascular disease (CVD). In 109 patients with severe OSA and no overt CVD, biomarkers of inflammation (C reactive protein, interleukin-6, tumour necrosis factor-α and its receptors, adiponectin, leptin and P-selectin), glucose and lipid metabolism, and N-terminal pro-brain natriuretic peptide, were measured before and after 2 months of treatment with a mandibular advancement device (MAD) (n=55) or a sham device (n=54). MAD reduced the Apnoea–Hypopnoea Index (p<0.001) but had no effect on circulating biomarkers compared with the sham device, despite high treatment adherence (6.6 hour/night)
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