Saint-Junien, France
Saint-Junien, France

Time filter

Source Type

Pandey S.J.,University of Central Florida | Martinez M.,University of Central Florida | Pelascini F.,CRITT Materiaux Alsace | Motto-Ros V.,University Claude Bernard Lyon 1 | And 2 more authors.
Optical Materials Express | Year: 2017

Strict control of composition is of paramount importance for the reproducible fabrication of advanced ceramics. In particular, the preparation of high-grade transparent ceramics of definite line-compounds requires that the ratio of major constitutive elements be quantified with a precision better than a fraction of a mole percent to prevent the precipitation of secondary phases and the scattering of light. Such a requirement poses difficult challenges to most analytical methods, especially when applied to nearly-stoichiometric insulating phases. In this work, we show that laser-induced breakdown spectroscopy (LIBS) is a wellsuited technique for the assessment of non-stoichiometry in yttrium aluminum garnet (YAG) ceramics and that the aluminum to yttrium ratio can be determined with a resolution of 0.3 mol %, well within the phase boundaries of YAG. © 2017 Optical Society of America.

Bandelier P.,CEA Grenoble | Pelascini F.,CRITT Materiaux Alsace | d'Hurlaborde J.-J.,Epteau | Maisse A.,CEA Grenoble | And 2 more authors.
Desalination and Water Treatment | Year: 2016

Combining low-grade solar heat source and polymer materials allows seawater desalination while fossil fuels are saved and use of chemicals against fouling and corrosion is reduced. SOLar Multi-Effect Desalination (SOLMED) project meets recommendations of the US National Research Council, Middle East Desalination Research Center of Oman and Australian Desalination research roadmap regarding the future of desalination. Water cost reduction and development of technologies with low environmental impact are the main guidelines of SOLMED. Low-temperature multi-effect distillation (LT-MED) is well known to be the most efficient distillation process. Coupling LT-MED with a solar heat source downstream of a CSP power plant allows to benefiting of a low marginal cost heat source. This paper presents the advancement of SOLMED project in which a full-polymer material MED desalination prototype is developed to be used with a low-temperature heat source. Operation and coupling parameters are calculated in order to minimize electricity and water total production cost. © 2016 Commissariat à l’Energie Atomique. All rights reserved.

Bandelier P.,CEA Grenoble | d'Hurlaborde J.-J.,Epteau | Pelascini F.,CRITT Materiaux Alsace | Martins M.,Sophia Antipolis Energie Developpement | And 4 more authors.
Desalination and Water Treatment | Year: 2015

Abstract: Combining thermal solar energy and polymer materials allows seawater desalination while fossil fuels are saved and use of chemicals against fouling and corrosion is reduced. SOLar Multi-Effect Desalination (SOLMED) meets recommendations of the US National Research Council and Middle East Desalination Research Center of Oman regarding the future of water desalination. Water cost reduction and development of technologies with low environmental impact are the main guidelines of SOLMED. Thermal efficiency is at the heart of SOLMED. Process is based on low-temperature multi-effect distillation (LT-MED) powered by a thermal solar collector field, or better, by heat recovery at the outlet of a solar power plant. Heat transfer surfaces are made of thin wall polymer tubes to ensure a high thermal duty in spite of low thermal conductivity of polymers. Targeted capacities lie within 500–1,000 m3/d. The objective is to develop a LT-MED prototype made of polymers and to operate the system plugged to a solar heat source. To reach these objectives, SOLMED gathers a consortium of six partners, merging experts of thermal systems and components, experts in polymers and transformation, and engineering partners in the field of solar energy and processes. Social aspects are also taken into account through acceptability, sustainability, design, management of innovation, market, and life cycle assessment. SOLMED is a three years project funded by the French National Research Agency. The first step is to build a 10 m3/d prototype to bring a proof of concept. The prototype will be operated with a 100 kW peak solar heat source. Developments are related to the modeling of the process itself and its integration in a solar system including heat storage, thin-wall tubes fabrication, optimization of tubes fixing, investigations related to heat transfer, and hydraulic. Regarding polymer materials, the challenge is to combine high thermal rate with long lifetime. Commercial step has to consider new optimization approach, taking into consideration the whole process, including heat source. © 2014 French Atomic Energy Commission. All rights reserved.

Gregoire S.,CRITT Materiaux Alsace | Gregoire S.,CNRS Research Laboratory for Historical Monuments | Boudinet M.,CRITT Materiaux Alsace | Pelascini F.,CRITT Materiaux Alsace | And 3 more authors.
Analytical and Bioanalytical Chemistry | Year: 2011

This study aims at differentiating several organic materials, particularly polymers, by laser induced breakdown spectroscopy. The goal is to apply this technique to the fields of polymer recycling and cultural heritage conservation. We worked with some usual polymers families: polyethylene (PE), polypropylene (PP), polyoxymethylene, (POM), poly(vinyl chloride), polytetrafluoroethylene, polyoxyethylene (POE), and polyamide for the aliphatic ones, and poly(butylene terephthalate), acrylonitrile-butadiene-styrene, polystyrene, and polycarbonate for the aromatic ones. The fourth harmonic of a Nd:YAG laser (266 nm) in ambient air at atmospheric pressure was used. A careful analysis of the C2 Swan system (0,0) band in polymers containing no C-C (POM), few C-C (POE), or aromatic C-C linkages led us to the conclusion that the C2 signal might be native, i.e., the result of direct ablation from the sample. With use of these results, aliphatic and aromatic polymers could be differentiated. Further data treatments, such as properly chosen line ratios, principal component analysis, and partial least squares regression, were evaluated. It was shown that many polymers could be separated, including PE and PP, despite their similar chemical structures. [Figure not available: see fulltext.] © 2011 Springer-Verlag.

Gregoire S.,CRITT Materiaux Alsace | Gregoire S.,CNRS Research Laboratory for Historical Monuments | Gregoire S.,Charles Sadron Institute | Motto-Ros V.,University Claude Bernard Lyon 1 | And 7 more authors.
Spectrochimica Acta - Part B Atomic Spectroscopy | Year: 2012

Emissions from C 2 molecules and CN radicals in laser-induced plasmas on polymeric materials were observed with time-resolved spectroscopic imaging. More precisely, differential imaging with a pair of narrowband filters (one centered on the emission line and another out of the line) was used to extract emission images of interested molecules or radicals. The correlation between the molecular emission image of the plasma and the molecular structure of the polymer to be analyzed was studied for four different types of materials: polyamide (PA) with native CN bonds, polyethylene (PE) with simple CC bonds, polystyrene (PS) with delocalized double CC bonds, and polyoxymethylene (POM) which neither contains CC nor CN bonds. A clear correlation is demonstrated between emission and molecular structure of the material, allowing the identification of several organic compounds by differential spectroscopic imaging. © 2012 Published by Elsevier B.V.

Bassel L.,Bordeaux Montaigne University | Motto-Ros V.,University Claude Bernard Lyon 1 | Trichard F.,University Claude Bernard Lyon 1 | Pelascini F.,CRITT Materiaux Alsace | And 5 more authors.
Environmental Science and Pollution Research | Year: 2016

Cave walls are affected by different kinds of alterations involving preservative issues in the case of ornate caves, in particular regarding the rock art covering the walls. In this context, coralloids correspond to a facies with popcorn-like aspect belonging to the speleothem family, mostly composed of calcium carbonate. The elemental characterization indicates the presence of elements that might be linked to the diagenesis and the expansion of the alterations as demonstrated by prior analyses on stalagmites. In this study, we report the use of laser-induced breakdown spectroscopy (LIBS) to characterize the elemental composition of one coralloid sample with a portable instrument allowing punctual measurements and a laboratory mapping setup delivering elemental images with spatial resolution at the micrometric scale, being particularly attentive to Mg, Sr, and Si identified as elements of interest. The complementarity of both instruments allows the determination of the internal structure of the coralloid. Although a validation based on a reference technique is necessary, LIBS data reveal that the external layer of the coralloid is composed of laminations correlated to variations of the LIBS signal of Si. In addition, an interstitial layer showing high LIBS signals for Fe, Al, and Si is interpreted to be a detrital clay interface between the external and the internal part of the coralloid. These preliminary results sustain a possible formation scenario of the coralloid by migration of the elements from the bedrock. © 2016 Springer-Verlag Berlin Heidelberg

Negre E.,University Claude Bernard Lyon 1 | Motto-Ros V.,University Claude Bernard Lyon 1 | Pelascini F.,CRITT Materiaux Alsace | Lauper S.,Institute National Of Police Scientifique | And 2 more authors.
Journal of Analytical Atomic Spectrometry | Year: 2015

The analytical figures of merit of laser-induced breakdown spectroscopy (LIBS) for elemental analysis of glass have been evaluated using a laboratory prototype of the LIBS instrument for the quantification of 4 elements, Ti, Cr, Ca and Ba. Two sets of samples were prepared or collected for the assessment. The first one consisted of 10 laboratory-prepared fused beads with the elemental content determined by X-ray fluorescence (XRF), an established analytical technique which was considered in our study as the reference technique for the assessment of the LIBS technique. Among them, 8 were used as reference samples and 2 as "unknown" samples for test. The calibration curves were thus established with the references. The counter calibration led to the determination of the elemental content in the unknown samples. Such a calibration procedure allowed assessing the figures of merit of LIBS together with the used setup and measurement protocol about a certain number of key parameters, such as the correlation with a linear regression of the calibration data, limit of detection (LoD), repeatability, reproducibility and relative accuracy. The second set of samples was collected from different origins and consisted of 8 bottle glass fragments, which were different in appearance (color and surface) and in content for the 4 analyzed elements. Their elemental concentrations were first determined using XRF. The LIBS calibration curves established with the fused beads were thus used to perform the analysis of 2 glass fragments with elemental contents lying around the range of the calibration concentration. Further analysis of the ensemble of glass fragments allowed assessing the matrix effect introduced by the different types of glasses and extending the calibration curves over a very large concentration range from several ppm to several percent. We show that the self-absorption effect observed over such a large concentration range can be taken into account by using quadratic regression. This journal is © The Royal Society of Chemistry.

Motto-Ros V.,University Claude Bernard Lyon 1 | Negre E.,University Claude Bernard Lyon 1 | Pelascini F.,CRITT Materiaux Alsace | Panczer G.,University Claude Bernard Lyon 1 | Yu J.,University Claude Bernard Lyon 1
Spectrochimica Acta - Part B Atomic Spectroscopy | Year: 2014

Improving the repeatability and the reproducibility of measurement with laser-induced breakdown spectroscopy (LIBS) is one of the actual challenging issues faced by the technique to fit the requirements of precise and accurate quantitative analysis. Among the numerous factors influencing the measurement stability in short and long terms, there are shot-to-shot and day-to-day fluctuations of the morphology of the plasma. Such fluctuations are due to the high sensitivity of laser-induced plasma to experimental conditions including properties of the sample, the laser parameters as well as properties of the ambient gas. In this paper, we demonstrate that precise alignment of the optical fiber for the collection of the plasma emission with respect to the actual morphology of the plasma assisted by real-time imaging, greatly improves the stability of LIBS measurements in short as well as in long terms. The used setup is based on a plasma imaging arrangement using a CCD camera and a real-time image processing. The obtained plasma image is displayed in a 2-dimensional frame where the position of the optical fiber is beforehand calibrated. In addition, the setup provides direct sample surface monitoring, which allows a precise control of the distance between the focusing lens and the sample surface. Test runs with a set of 8 reference samples show very high determination coefficient for calibration curves (R2 = 0.9999), and a long term repeatability and reproducibility of 4.6% (relative standard deviation) over a period of 3 months without any signal normalization. The capacity of the system to automatically correct the sample surface position for a tilted or non-regular sample surface during a surface mapping measurement is also demonstrated. © 2013 Elsevier B.V.

Negre E.,University Claude Bernard Lyon 1 | Motto-Ros V.,University Claude Bernard Lyon 1 | Pelascini F.,CRITT Materiaux Alsace | Yu J.,University Claude Bernard Lyon 1
Spectrochimica Acta - Part B Atomic Spectroscopy | Year: 2016

A method of rapid classification and identification of plastic materials has been studied in this work. Such method is based on fast spectroscopic imagery of laser-induced ablation plume on plastics to be analyzed. More specifically, a classification schema has been developed first according to the nature of the CC bonds which characterize the polymer matrix. Our results show that the spatial distribution and the evolution of the molecular species in the ablation plume, such as C2 and CN, exhibit clear different behaviors for polymers without any native CC bond, with CC single bonds or with CC double bonds respectively. Therefore the morphological parameters of the populations of the molecular species extracted from the time-resolved spectroscopic images of the plumes provide efficient indicators to classify the polymers characterized by the above mentioned different kinds of CC bonds. When dealing with different polymers with the same kind of CC bond, CC single bond for instance, other indicators should be introduced to provide the further discrimination. Such indicators can be for example a specific native molecular bond other than CC bonds, CN for example, the total emission intensity of which may exhibit specific time evolution. The robustness of the developed classification schema has been then studied with respect to two of the most frequently used additives in plastics fabrication, graphite and titanium. Our results show a negligible influence of these additives in the morphology of the populations of the molecular species when such additives are mixed into the polymer matrix with the percentages usually used in plastics productions, which demonstrates the validity of the developed classification schema for plastics. © 2016 Published by Elsevier B.V.

Loading CRITT Materiaux Alsace collaborators
Loading CRITT Materiaux Alsace collaborators