Search results for "Argo"
showing 10 items of 424 documents
Gas sensing properties of multiwall carbon nanotubes decorated with rhodium nanoparticles
2011
International audience; In the present work, multiwalled carbon nanotubes were decorated with rhodium nanoparticles using a colloidal solution in the post-discharge of an RF atmospheric plasma of argon (Ar) or argon/oxygen (Ar:O 2). The properties of these hybrid materials towards the room temperature detection of NO 2 , C 2 H 4 , CO, C 6 H 6 and moisture were investigated and discussed in view of compositional and morphological studies. It was found that the presence of oxygen in the plasma treatment is essential to significantly enhance the gas response of Rh-decorated multiwalled carbon nanotubes and to avoid response saturation even at low gas/vapor concentrations. These desirable effec…
Oxidation of pentan-2-ol -Part II: Experimental and modeling study
2021
International audience; The oxidation of pentan-2-ol was investigated at high-pressure in a jet-stirred reactor and in a shock tube. Experiments in the JSR were carried out at 10 atm, between 500-1180 K, for five different equivalence ratios of = 0.35, 0.5, 1, 2, 4 and 1000 ppm of fuel, at a constant residence time of 0.7 s. Reactant, product and intermediate species mole fractions were quantified using Fourier transform infrared spectrometry (FTIR) and gas chromatography (GC). Ignition delay times were measured for pentan-2-ol/O 2 mixtures in argon in a shock tube at 20 and 40 bar, in a temperature range of 1070-1460 K and for equivalence ratios of = 0.5, 1 and 2. Ignition delay times of a…
Potential of amorphous Mo–Si–N films for nanoelectronic applications
2003
The properties of amorphous metallic molybdenum–silicon–nitrogen (Mo–Si–N) films were characterised for use in nanoelectronic applications. The films were deposited by co-sputtering of molybdenum and silicon targets in a gas mixture of argon and nitrogen. The atomic composition, microstructure and surface roughness were studied by RBS, TEM and AFM analyses, respectively. The electrical properties were investigated in the temperature range 80 mK to 300 K. No transition into a superconductive state was observed. Nanoscale wires were fabricated using electron beam lithography with their properties measured as a function of temperature.
High vibrational overtone excitation‐induced conformational isomerization of glycolic acid in solid argon matrix
2018
Energy and entropy barriers of two-level systems in argon clusters: An energy landscape approach
1999
Abstract Free argon clusters containing up to 160 atoms have been studied by means of a numerical algorithm for finding thousands of adjacent minima connected through a first-order saddle point. Many minimum-saddle-minimum systems have been found to be good candidates for forming two-level systems. The ground state splitting has been evaluated by taking into account both energy and entropy barriers. The role of the latter in auenching or enhancing the ground state splitting is discussed with the aid of a simple model potential.
Assessing the competence learning to learn: a methodological proposal
2012
En este artículo se presenta un procedimiento para diseñar instrumentos para evaluar la competencia de Aprender a Aprender. Analizamos la secuencia de trabajo y los conceptos implicados. Se trata de una línea de trabajo que pretende diseñar instrumentos de evaluación referidos a estándares, para evaluar las competencias básicas en la educación obligatoria, y las genéricas o transversales en las titulaciones de grado universitarias (el sistema de instrumentos para universitarios se denomina ESCOGE). Se ilustra la reflexión acerca de esta propuesta con la definición teórica realizada para el diseño de instrumentos que permitan evaluar esta competencia en egresados universitarios del área de C…
Long-term organic farming on a citrus plantation results in soil organic carbon recovery
2019
[ES] Se ha demostrado que el manejo del suelo bajo agricultura ecológica puede aumentar el contenido de carbono orgánico en el suelo moderando el incremento de los gases de efecto invernadero, pero hasta la fecha las evaluaciones cuantitativas basadas en mediciones a largo plazo han sido escasas, especialmente bajo condiciones mediterráneas. En esta investigación se examinaron los cambios en el contenido de carbono orgánico como respuesta a la agricultura ecológica con cobertura vegetal en una plantación de cítricos en el área mediterránea, utilizando una base de datos de 21 años. El incremento de contenido de carbono orgánico en el suelo fue más evidente tras cinco años desde el cambio del…
Diet of Risso's dolphin (<i>Grampus griseus</i>) in the western Mediterranean Sea
2006
The diet of Risso’s dolphin in the Mediterranean is described based on 15 animals stranded between 40°25’N 00°32’W and 37°35’N 00°45’E from April 1987 to January 2003. The prey were mainly oceanic cephalopods. Pelagic octopods, especially A. argo, were the most abundant (mean = 41.28%; SD±34.32). Species belonging to the families Ommastrephidae, Histioteuthidae and Onychoteuthidae were also frequent components of its diet. The bathymetric distribution of cephalopods shows that Risso’s dolphin preferentially feeds on the middle slope (600 to 800 m depth) in the Mediterranean.
The alien vascular flora of Stromboli and Vulcano (Aeolian Islands, Italy)
2021
The updated censuses of the alien flora of the islands of Stromboli and Vulcano, Aeolian Islands in the Central Tyrrhenian Sea, are presented here. They currently consist of 40 and 57 specific and subspecific taxa respectively. As many as 16 and 18 taxa respectively are new in comparison with the last censuses in 2016. Mesembryanthemum × vascosilvae, commonly cultivated in both islands, is reported for the first time as naturalized alien to Italy. Passiflora incarnata from Stromboli and Pelargonium graveolens from Vulcano are reported for the first time as casual aliens to Sicily. The evolution over time of these florulas, as inferred from the main floristic works published on these islands…
High Temperature Study of Metamict Rinkite
2013
Metamict minerals contain radioactive elements that degrade their crystal structure. During the annealing process under ambient pressure in argon atmosphere the sample of metamict rinkite recrystallizes to the primary crystalline form at 700°C. Further heating leads to the formation of a new crystalline phase.