Search results for "Engineering sciences"
showing 10 items of 2347 documents
SAW based CO2 sensor: influence of functionalizing MOF crystal size on the sensor's selectivity
2021
International audience; The potential impact of indoor air quality on human health has become an increasingly important topic of public health and, thus, has stimulated an interest in hazardous compounds survey such as carbon dioxide. To address this issue, we started the development of a Surface Acoustic Wave device functionalized with metal-organic framework for the selective detection of carbon dioxide. Here, we propose preliminary results on the influence of the size of the metal-organic framework crystals on the sensor’s selectivity and on its evolution with the ageing of the sensor
Electrochemistry of Mono- and Bis-CN Ligated Cobalt Corroles
2021
International audience; The electrochemical properties of numerous transition metal corroles have been examined under a variety of<br>solution condition with special emphasis being placed on the innocent or non-innocent nature of the corrole<br>macrocycle. This property, as well as the half-wave potentials and sites of electron transfers, are known to be<br>strongly influenced by the type of central metal ion and degree of axial coordination, namely 4, 5 or 6-coordinate.<br>The redox potentials of metallocorroles are also dependent upon the solvent and inductive, resonance or steric<br>effects dictated by peripheral substituents at the meso or β-pyrrole positions of the corrole li…
Porous Organic Polymers (POPs) based on cobalt corroles for the detection of carbon monoxide
2021
International audience; Detection of carbon monoxide (CO) at few ppm levels is a critical point for quality control of domestic and<br>industrial environment. CO is responsible for thousands of intoxications and hundreds of deaths per year in the<br>world. Moreover, CO is a residual gas found in the industrial dihydrogen used for Proton Exchange Membrane<br>fuel cell, and deactivates the fuel cell prematurely. Corroles have been largely used in sensing applications.[1]<br>Cobalt corroles display high binding affinity for carbon monoxide even in the presence of nitrogen and<br>dioxygen.[2] The affinity of the Co(III) metallocorroles for CO is directly correlated with the Lewis acid…
Rétine Vidéo Rapide Réalisée en Technologie CMOS
2008
Nous présentons une rétine réalisée en technologie CMOS 0.6 μm dédiée à l’observation de phénomènes lumineux rapides. Le pixel que nous avons conçu est basé sur un principe de modulation de la durée d’une impulsion représentative du flux lumineux incident. Ce pixel a été validé par simulation SPICE grâce aux bibliothèques AMS du fondeur puis dessiné en full- custom de façon à optimiser sa surface, on a obtenu ainsi un pixel dont la dimension est de 49.2μm de coté avec un taux de remplissage de 18 %.
An alternative way to improve the sensitivy of electronic olfactometers
1999
International audience
A fast and reproducible for gas sensor screening to flavour compounds
1995
International audience
Etude numérique du comportement thermique d’un séchoir solaire utilisant un lit thermique pour le stockage d’énergie
2018
This thesis presents a numerical study of an indirect natural convection solar dryer for drying agricultural products (Figs). The first part analyzes a solar dryer containing a drying chamber coupled to a reversed absorber and a solar chimney. Simulations were made to determine the dynamic and thermal fields under the influence of the variation of the solar chimney configuration and the size of the inlet opening. The governing equations based on the standard k-ε turbulence model are solved by the finite volume method using the ANSYS-Fluent commercial code. The second part analyzes the effect of adding a thermal storage in the form of a gravel bed in the drying chamber. The bed is modeled as…
Experimental and theoretical studies on electropolymerization of polar amino acids on platinum electrode
2017
International audience; The anodic oxidation of polar amino acids (L-serine, L-threonine, L-asparagine, and L-glutamine) in aqueous electrolyte on smooth platinum electrode was carried out by cyclic voltammetry coupled to electrochemical quartz crystal microbalance (EQCM). pH (zwitterion, acidic and alkaline) effects on their electrochemical behavior were examined. The maximum current values are measured for zwitterion species. In addition, the current increases with increasing of concentration and scan rate, and decreases with increasing pH. The resulting passivation was studied by spectroscopic analysis such as attenuated total reflection FT infrared spectroscopy (ATR-FTIR), X-ray photoel…
Electrochemistry of Bis(pyridine)cobalt (Nitrophenyl)corroles in Nonaqueous Media
2018
International audience; A series of bis(pyridine)cobalt corroles with one or three nitrophenyl groups on the meso positions of the corrole macrocycle were synthesized and characterized as to their electrochemical and spectroscopic properties in dichloromethane, benzonitrile, and pyridine. The potentials for each electrode reaction were measured by cyclic voltammetry and the electron-transfer mechanisms evaluated by analysis of the electrochemical data combined with UV-visible spectra of the neutral, electroreduced, and electroxidized forms of the corroles. The proposed electronic configurations of the initial compounds and the prevailing redox reactions involving the electroactive central c…
Quantification of land-atmosphere exchanges of water, energy and carbon dioxide in space and time over the heterogeneous Barrax site
2008
International audience; To advance our understanding of land-atmosphere exchanges of water, energy and carbon dioxide (CO2) in space and time over heterogeneous land surfaces, two intensive field campaigns were carried out at the Barrax agricultural test site in Spain during 12-21 July 2004 (SPARC 2004) and 8-14 July 2005 (SEN2FLEX 2005) involving multiple field, satellite and airborne instruments for characterizing the state of the atmosphere, the vegetation and the soil from the visible to the microwave range of the spectrum. Part of the experimental area is a core site of area 25 km2, within which numerous crops are grown, on both irrigated and dry land, alongside fields of bare soil. Th…