Search results for "RAV"
showing 10 items of 5866 documents
The Role of Covalent Functionalization in the Thermal Stability and Decomposition of Hybrid Layered Hydroxides
2020
The room temperature synthesis of two Co-based hybrid layered hydroxides containing the same organic ligand (suberate [Sub]), one connected through purely electrostatic interactions (CoAl layered double hydroxide [LDH]), and the other covalently functionalized (α-CoII simonkolleite phase) has been carried out. The magnetic properties exhibit an acute difference in the magnetization temperatures (from ≈10 K for the CoAl-LDH to ≈55 K for the α-CoII). Moreover, the role of the covalent functionalization in the thermal stability and the decomposition has been investigated by a forefront characterization tool consisting of thermogravimetric analysis coupled with gas chromatography and mass spect…
SOLUTRENSES DEL SUR DE IBERIA EN TRANSICIÓN
2013
La cuestión de las relaciones tecnoeconómicas entre el Solutrense y los complejos que lo enmarcan (Gravetiense y Badeguliense) permanence abierta y condicionada por los procesos erosivos que coinciden con estos momentos en la mayoría de yacimientos de la región mediterránea ibérica. El análisis de las industrias líticas de Parpalló y Nerja, así como el conjunto de las dataciones radiocarbónicas permite una aproximación a estas relaciones y una evaluación crítica de su marco cronológico.The relationship between the Solutrean and the Gravettian and Badegoulian is still an open issue, and the analysis of this relationship in most sites appears to be conditioned by the effects of erosive proces…
Direct seeding mulch-based cropping increases both the activity and the abundance of denitrifier communities in a tropical soil
2009
International audience; This study evaluated the impact of direct seeding mulch-based cropping (DMC), as an alternative to conventional tilling (CT), on a functional community involved in N cycling and emission of greenhouse gas nitrous oxide (N2O). The study was carried out for annual soybean/rice crop rotation in the Highlands of Madagascar. The differences between the two soil management strategies (direct seeding with mulched crop residues versus tillage without incorporation of crop residues) were studied along a fertilization gradient (no fertilizer, organic fertilizer, organic plus mineral fertilizers). The activity and size of the denitrifier community were determined by denitrifica…
Incomplete self-similarity and flow velocity in gravel bed channels
2000
Velocity measurements, previously carried out using both a miniature current flowmeter and an acoustic Doppler velocimeter, are used to verify the applicability of the incomplete self-similarity theory to deduce the velocity profile in a gravel bed channel. Then, for the velocity profiles having the maximum value below the free surface and for the S-shaped profiles, the power velocity distribution is corrected using a new divergence function. For each value of the depth sediment ratio the nondimensional friction factor parameter is calculated by integration of the measured velocity distributions in the different verticals of the cross section. Finally, a semilogarithmic flow resistance equa…
2020
Background Physical activity trackers (PATs) such as apps and wearable devices (eg, sports watches, heart rate monitors) are increasingly being used by young adolescents. Despite the potential of PATs to help monitor and improve moderate-to-vigorous physical activity (MVPA) behaviors, there is a lack of research that confirms an association between PAT ownership or use and physical activity behaviors at the population level. Objective The purpose of this study was to examine the ownership and use of PATs in youth and their associations with physical activity behaviors, including daily MVPA, sports club membership, and active travel, in 2 nationally representative samples of young adolescen…
Analyse expérimentale et numérique du comportement de véhicules terrestres en présence d'un vent latéral instationnaire
2013
The automotive manufacturers are nowadays more and more interested in crosswind aerodynamics. Indeed, the driver is subjected every day to strong side air flows, for example when overtaking another vehicle or when passing through a lateral wind wall, generated by terrain topography (as in the case of the passage near the empty space between two buildings).The aerodynamic efforts generated in these situations can lead to undesired lateral deviations,which can be dramatic if the driver is surprised. Different experimental studies, reproducing the effects of a dynamic yaw angle, pointed out the issues of the steady methods, commonly used to qualify the vehicle crosswind behaviour. Little is st…
Photostimulated processes in the CsI-Tl crystal after UV irradiation
1997
The photostimulated luminescence is studied for CsI-Tl crystal after irradiation with ultraviolet light in the 80 - 300 K temperature range. The PSL creation spectrum coincides with the D absorption band at 80 K. Three bands are observed in the stimulation spectra at 80 K: 1400, 950, and 600 nm. The 1400 and 950 nm stimulation bands are presumably explained as optical transitions in the Tl 0 and V k centers situated in the spatial correlated pairs. The stimulation at 600 nm band is ascribed to the unperturbed Tl 0 centers.
Protective Effects of L- and D-Carnosine on R-Crystallin Amyloid Fibril Formation: Implications for Cataract Disease
2009
Mildly denaturing conditions induce bovine ?-crystallin, the major structural lens protein, to self-assemble into fibrillar structures in vitro. The natural dipeptide L-carnosine has been shown to have potential protective and therapeutic significance in many diseases. Carnosine derivatives have been proposed as potent agents for ophthalmic therapies of senile cataracts and diabetic ocular complications. Here we report the inhibitory effect induced by the peptide (L- and D-enantiomeric form) on ?-crystallin fibrillation and the almost complete restoration of the chaperone activity lost after denaturant and/or heat stress. Scanning force microscopy (SFM), thioflavin T, and a turbidimetry ass…
Marché de travaux privés : caractère spécifique du cautionnement solidaire et inopposabilité de l'extinction de la créance
2002
International audience; (Cass. 3e civ., 3 oct. 2001, CRCAM c/ Sté HLM de Grand-Quevilly, pourvoi n° 99-18.080, arrêt n° 1377 FS-P + B, D. 2001, AJ p. 3121, obs. A. Lienhard)
La créativité dans les premiers emplois en temps de crise: distribution inégale d'une compétence requise
2016
International audience; Dans une économie en crise et face à la fragilisation des parcours d'insertion professionnelle des jeunes (Galland, 1991), marqués de multiples bifurcations (Bidart, 2010a), l'économie se demande comment mieux équiper les individus pour réduire les inégalités face au marché de l'emploi. La créativité, en tant que modalité de l'action permettant d'engendrer des changements dans la sphère politique (Joas, 2001), associée à l'innovation, nécessaire dans des secteurs d'emploi en expansion, a pu apparaître comme une compétence requise en temps de crise, bénéficiant potentiellement aux travailleurs comme aux organisations qui les emploient. La créativité, qu'Aristote prése…