Search results for " characterization"
showing 10 items of 310 documents
Colorimetric Characterization of a Positive Film Scanner Using an Extremely Reduced Training Data Set
2011
International audience; In this work, we address the problem of having an accurate colorimetric characterization of a scanner for traditional posi- tive film in order to guarantee the accuracy of the color informa- tion during the digitization of a movie. The scanning of a posi- tive film is not an usual task, however it can happen for cultural heritage purpose. Art-movies, are often created and stored as positive-film in museums. One of the problems one can face for a colorimetric characterization is to have a reasonable number of measurements from an item. In this work we succeeded in having a reasonable accuracy with just a few number of measurement (typically 4 to 7 ∆Ea∗b units with 2 t…
Characterization of a bean landrace from Sicily: the ‘fagiolo Badda di Polizzi'
2008
Inside the project “Piano per la Produzione di Proteine Vegetali in Sicilia” investigations were carried out to characterize a bean population cultivated in the Parco delle Madonie area, the ‘Fagiolo Badda di Polizzi’. The producers’ interest for this landrace and the appreciation of the consumers could justify the start up of a valorization program through a product certification. Researches on the morpho-physiological aspects and on the nutritional profile were made in trials conducted between 2005 and 2007. All the Badda bean accessions showed an indeterminate plant growth habit, white flowers and a very delayed flowering time. In particular, a certain variability was seen and described …
Electrochemical and Spectroelectrochemical Properties of Free-Base Pyridyl- and N -Alkyl-4-Pyridylporphyrins in Nonaqueous Media
2015
International audience; Twelve structurally related pyridyl and meso-N-methylpyridylporphyrin derivatives are investigated electrochemically in different nonaqueous media. The UV/Vis spectrum of each newly investigated porphyrin was measured before and after electro-reduction and, based on this data, the site of electron transfer is proposed. An interaction occurs between the meso-pyridyl or meso-N-alkyl-4-pyridyl substituents and the porphyrin p-ring system, the magnitude of which depends upon the number of linked pyridyl or N-alkyl-4-pyridyl groups in the compound, the solvent, the supporting electrolyte, and/or other anions added to the solution.
Current characterisation for ultra low power wireless body area networks
2010
The emerging area of body area networks (BAN) imposes challenging requirements on hardware and software to achieve the desired lifetimes for certain devices such as long term medical implants. In this paper, we propose a novel approach to the measurement and characterisation of the energy consumption of BAN devices. The approach uses a low cost energy auditing circuit and addresses the problem of accurately measuring low-level current consumption. This new technique will allow precise and analytical measurements of systems and components in terms of energy. This will help circuit designers minimise power consumption in BAN devices. Software engineers might use this approach to validate and …
Characterization of a digital camera as an absolute tristimulus colorimeter
2003
An algorithm is proposed for the spectral and colorimetric characterization of digital still cameras (DSC) which allows them to be used as tele-colorimeters with CIE-XYZ color output, in cd/m2. The spectral characterization consists in the calculation of the color-matching functions from the previously measured spectral sensitivities. The colorimetric characterization consists in trans- forming the raw RGB digital data into absolute tristimulus values CIE-XYZ (in cd/m2) under variable and unknown spectroradiometric conditions. Thus, in the first stage, a gray balance was applied over the raw RGB digital data to convert them into RGB relative colorimetric values. In the second stage, an algo…
Effect of Pre-Reduction on the Properties and the Catalytic Activity of Pd/Carbon Catalysts: A Comparison with Pd/Al2O3
2013
The effect of pre-reduction in solution with chemical reagents on the catalytic performance and catalyst properties of Pd/carbon catalysts was systematically investigated with a multitechnique approach. The results are critically discussed in comparison to those recently obtained on analogous Pd/alumina catalysts. It was proved that the Pd phase on the carbon surface is characterized by a high mobility, opposite to what occurs on alumina. As a result, the Pd particles on carbon aggregate together during pre-reduction, with a consequent decrease in available metal surface. Pd particles remain aggregated also in reaction conditions; the decreased Pd dispersion negatively affects the catalyst …
Unexpected Structural Diversity in Alkali Metal Azide-Crown Ether Complexes: Syntheses, X-ray Structures, and Quantum-Chemical Calculations
2005
A series of alkali metal azide-crown ether complexes, [Li([12]crown-4)(N-3)], [Na([15]crown-5)(N-3)], [Na([15]crown-5)(H2O)(2)]N-3, [K([18]crown-6)(N-3)(H2O)], [Rb([18]crown-6)(N-3)(H2O)], [Cs([18]crown-6)(N-3)](2), and [Cs([18]crown-6)(N-3)(H2O)(MeOH)], has been synthesised. In most cases, single crystals were obtained, which allowed X-ray crystal structures to be derived. The structures obtained have been compared with molecular structures computed by density functional theory (DFT) calculations. This has allowed the effects of the crystal lattice on the structures to be investigated. Also, a study of the M-N-terminal metalazide bond length and charge densities on the metal (M) and termin…
Morphology, rheology, and mechanical properties of a new nanobiocomposite
2015
Nanobiocomposites are a new class of biodegradable polymer materials with an ultrafine phase dispersion of the order of a few nanometers in a biodegradable polymer matrix that shows very interesting properties often very different from those of conventional filled polymers. In this work the morphology and the rheological and mechanical properties of a new nanobiocomposite made of a biodegradable copolyester based blend with an organomodified montmorillonite have been investigated to evaluate its possible use in several applications. SAXS diffractograms and TEM micrographs show that the in both the adopted processing conditions an hybrid intercalated/exfoliated morphology is observed. Rheolo…
Characterization of ultra-high-molecular-weight polyethylene (UHMWPE) modified by ion implantation
2004
Abstract Surface modification of ultra high molecular weight polyethylene (UHMWPE) is induced by ion implantation of different ions at 300 keV energy. The aim of this work was the chemical, physical and mechanical characterization of the modified material in order to know deep inside about the effect of the ion beam upon the polymer. The irradiated surfaces are investigated by Raman spectroscopy, infrared absorption and micro-hardness analysis, scanning electron microscopy. Pin on disc measurements valuated the wear of the UHMWPE against a stainless steel probe; wear resistance increases of about 76% after the ion implantation. This result can be attributed to the ion bombardment inducing a…
Complex composite structures with integrated piezoelectric transducers
2016
International audience; Nowadays, in different industrial fields as transport or aerospace, a research effort is conducted to reduce the structural weight. One of the most promising solutions is the use of composite structures due to their high stiffness, their low mass density and their low damping factor. At the same time, there is an intensification of the operational dynamic environment and an increase of durability requirements. These different expectations seem to be contradictory. One solution to manage these points is to design and manufacture smart composite structures with a fully distributed set of integrated piezoelec-tric transducers. These structures are able to modify their m…