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1. Climbing for dummies: recommendation for multi‐specific fishways for the conservation of tropical eels and gobies

Author

Raphaël Lagarde, Dominique Courret, Henri Grondin, Dominique Ponton, Laetitia Faivre, Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Office français de la biodiversité (OFB), Institut de mécanique des fluides de Toulouse (IMFT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), OCEA Consult', Ecologie marine tropicale dans les Océans Pacifique et Indien (ENTROPIE [Réunion]), Institut de Recherche pour le Développement (IRD)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut Français de Recherche pour l'Exploitation de la MER - IFREMER (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), OCEA Consult (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Poitiers (FRANCE), Université de La Réunion (FRANCE), Office français de la biodiversité - OFB (FRANCE), Université de la Nouvelle Calédonie - UNC (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), and Ecologie marine tropicale des océans Pacifique et Indien - ENTROPIE (Tuléar, Madagascar)

Subjects
0106 biological sciences, food.ingredient, Fishways, Ingénierie de l'environnement, Cotylopus acutipinnis, 010603 evolutionary biology, 01 natural sciences, food, 14. Life underwater, River continuum, Nature and Landscape Conservation, Fish migration, Amphidromy, Eels, Dam, Ecology, biology, [SDE.IE]Environmental Sciences/Environmental Engineering, 010604 marine biology & hydrobiology, Catadromy, Tropics, Sicyopterus lagocephalus, biology.organism_classification, Fishery, Substrate type, Upstream passage, Climbing, Environmental science, %22">Fish , Sicydiinae
Abstract

International audience; Dams and other man-made barriers impair upstream fish migration and thus threaten fish populations that need access to upper river reaches to complete their life cycle. For many years, fishways have been used to mitigate this impact. Fishways around the globe are typically built based on recommendations made for northern hemisphere species, particularly salmonids. These recommendations do not consider the locomotor characteristics and skills of other species, especially those living in the tropics. Among tropical species, freshwater eels and gobies of the Sicydiinae subfamily are important cultural and economic species that are particularly sensitive to the impact of man-made barriers. Our experimental study aimed to test different substrates and slopes for ramp-like fishways adapted to tropical eels and sicydiines. Among the five substrates tested for 368 eels Anguilla marmorata, elastomer pins appeared to be the most efficient. Elastomer pins also appeared to be more efficient than the fine concrete which is currently used in fishways for sicydiines (Sicyopterus lagocephalus, N = 1797, and Cotylopus acutipinnis, N = 1303). The slope had a lesser effect on the climbing success of sicydiines compared to substrate type, except for gradients greater than 50° that induced a slight decrease in success. Our results indicated that ramp-like fishways fitted with 1.0 cm diameter elastomer pins, positioned in staggered rows with a diagonal spacing of 1.3 cm, wetted with low-flow and angled less than 50°, are well adapted to accommodate the different locomotor characteristics and skills of tropical eels and sicydiines.

Published
2021

2. Quasi-Variational Inequality Problems over Product Sets with Quasi-monotone Operators

Author

K. Cao Van, David Salas Videla, Didier Aussel, Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Génie Chimique (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), and Institut National Polytechnique de Toulouse - INPT (FRANCE)

Subjects
Pure mathematics, Current (mathematics), 0211 other engineering and technologies, Quasi-monotone operator, Monotonic function, 010103 numerical & computational mathematics, 02 engineering and technology, Fixed point, Mathematical proof, 01 natural sciences, Theoretical Computer Science, [CHIM.GENI]Chemical Sciences/Chemical engineering, Operator (computer programming), Quasi-variational inequality, Product sets, Génie chimique, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, [MATH]Mathematics [math], 0101 mathematics, Génie des procédés, Mathematics, Net-lower sign-continuity, 021103 operations research, Fixed points, Monotone polygon, Product (mathematics), Variational inequality, Stability, Software
Abstract

International audience; Quasi-variational inequalities are variational inequalities in which the constraint map depends on the current point. Due to this characteristic, specific proofs have been built to prove adapted existence results. Semicontinuity and generalized monotonicity are assumed and many efforts have been made in the last decades to use the weakest concepts. In the case of quasi-variational inequalities defined on a product of spaces, the existence statements in the literature require pseudomonotonicity of the operator, a hypothesis that is too strong for many applications, in particular in economics. On the other hand, the current minimal hypotheses for existence results for general quasi-variational inequalities are quasi-monotonicity and local upper sign-continuity. But since the product of quasi-monotone (respectively, locally upper sign-continuous) operators is not in general quasi-monotone (respectively, locally upper sign-continuous), it is thus quite difficult to use these general-type existence result in the quasi-variational inequalities defined on a product of spaces. In this work we prove, in an infinite-dimensional setting, several existence results for product-type quasi-variational inequalities by only assuming the quasi-monotonicity and local upper sign-continuity of the component operators. Our technique of proof is strongly based on an innovative stability result and on the new concept of net-lower sign-continuity.

Published
2019

3. Dense upflow fluidized bed (DUFB) solar receivers of high aspect ratio: Different fluidization modes through inserting bubble rupture promoters

Author

Raf Dewil, Gilles Flamant, Yimin Deng, Jan Baeyens, Renaud Ansart, Alex Le Gal, Shuo Li, Ronny Gueguen, Florian Sabatier, Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Beijing University of Chemical Technology, University of Western Ontario (UWO), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Beijing University of Chemical Technology - BUCT (CHINA), Katholieke Universiteit Leuven - KU LEUVEN (BELGIUM), Université de Perpignan Via Domitia - UPVD (FRANCE), and Laboratoire de Génie Chimique - LGC (Toulouse, France)

Subjects
Materials science, General Chemical Engineering, Bubble, Particle-in-tube solar receivers, 02 engineering and technology, Heat transfer coefficient, 010402 general chemistry, 01 natural sciences, Industrial and Manufacturing Engineering, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], Physics::Fluid Dynamics, Bubble rupture promoters, Slugging, Gas through flow, Génie chimique, Environmental Chemistry, Two Fluid Model and sub-grid model, Fluidization, Génie des procédés, Fluidization regimes, ComputingMilieux_MISCELLANEOUS, Turbulence, General Chemistry, Mechanics, Chemical reactor, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Fluidized bed, CFD simulation, Heat transfer, 0210 nano-technology
Abstract

A fluidized bed of Geldart-A particles is promoted as heat transfer fluid in the tubular solar receivers of solar towers. A pressure-driven upward particle flow affects the hydrodynamic flow structure and properties of the fluidized bed. Experiments involved a tube of 0.05 m internal diameter but of very high height/diameter ratio (>120), representative of the future solar receiver and of numerous chemical reactors. Solid circulation fluxes and aeration velocities were varied. Configurations of a bare tube and a tube with bubble rupture promoters were compared. In the bare tube, freely bubbling is transformed into axi-symmetric slugging at a bed level of ~1 m. With bubble rupture promoters, freely bubbling prevails to about a bed level of 3 m, and a turbulent fluidization mode develops higher up the tube (a more chaotic two-phase system with elongated and unstable “gas voids” and “dense solid clusters”), without axi-symmetric slugging detected. Experimental results for both tube configurations were assessed and compared with CFD predictions by the Euler n-fluid code, NEPTUNE_CFD. A good agreement of bed properties was obtained for slug/void frequencies and solids volume fraction in both tube configurations. BRPs moreover enhance the bubble through flow of the fluidizing gas, thus limiting the visible bubble flow rate and bubble sizes while increasing the gas/particle contact, and hence important in designing multi-tube chemical reactors. Whereas slugging limits the heat transfer from the tube wall to the suspension at ~200 W/m2K, the presence of BRPs maintains a heat transfer coefficient in excess of 600 W/m2K.

Published
2021

4. Oxidation and high-temperature radiative properties of the Kanthal Super ER intermetallic alloy

Author

Johann Colas, Ludovic Charpentier, Jérôme Esvan, Eric Bêche, Danying Chen, Flavien Mercier, Domingos De Sousa Meneses, Michel Pons, Marianne Balat-Pichelin, Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Science et Ingénierie des Matériaux et Procédés (SIMaP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Conditions Extrêmes et Matériaux : Haute Température et Irradiation (CEMHTI), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université d'Orléans (UO), ANR-16-CE08-0019,2MAC-CSP,Revêtements Avancés Multicouches Multifonctionnels pour les Centrales Solaires à Concentration(2016), Laboratoire procédés, matériaux et énergie solaire (PROMES-CNRS), Université d'Orléans (UO)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut polytechnique de Grenoble (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
Materials science, Intermetallics, 020209 energy, General Chemical Engineering, Matériaux, Alloy, Intermetallic, 02 engineering and technology, Temperature cycling, engineering.material, 7. Clean energy, Corrosion, [SPI.MAT]Engineering Sciences [physics]/Materials, Critical point (thermodynamics), Oxidation, 0202 electrical engineering, electronic engineering, information engineering, Emissivity, XPS, General Materials Science, ComputingMilieux_MISCELLANEOUS, B. SEM, Solar furnace, Metallurgy, A. Intermetallics, Thermal cycling, C. Oxidation, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, B. Thermal cycling, Creep, B. Raman spectroscopy, SEM, Raman spectroscopy, engineering, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, 0210 nano-technology, B. XPS
Abstract

International audience; The oxidation resistance of receivers is a critical point in the development of plants using solar tower technology. Intermetallics in Mo-Si-Al system present oxidation maximum temperature and creep resistance superior to the ones of the currently used Ni-based alloys. We followed here the oxidation resistance of such intermetallic exposed to different treatments in air: long-term oxidation (up to 700 h) at 1373 K, and for several cycles of 20 minutes in solar furnace. The normal spectral emissivity is measured up to 1640 K in air, and our main positive conclusion is this property is not degraded by the oxidation.

Published
2021

5. Bio-energy Carriers as Back-up Fuel in Hybrid Solar Power Plants

Author

Jan Baeyens, Renaud Ansart, Yimin Deng, Gilles Flamant, Raf Dewil, Huili Zhang, Shuo Li, Centre National de la Recherche Scientifique - CNRS (FRANCE), European Powder and Process Technology - EPPT (BELGIUM), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Beijing University of Chemical Technology - BUCT (CHINA), Katholieke Universiteit Leuven - KU LEUVEN (BELGIUM), Université de Perpignan Via Domitia - UPVD (FRANCE), Laboratoire Procédés, Matériaux et Energie Solaire - PROMES (Perpignan, France), Beijing University of Chemical Technology, Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université Fédérale Toulouse Midi-Pyrénées

Subjects
Energy carrier, business.industry, 020209 energy, Biomass, 02 engineering and technology, 021001 nanoscience & nanotechnology, Thermal energy storage, 7. Clean energy, Reliability (semiconductor), [CHIM.GENI]Chemical Sciences/Chemical engineering, Hybrid Solar Power, Concentrated solar power, 0202 electrical engineering, electronic engineering, information engineering, Environmental science, Génie chimique, Bio-energy, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Electricity, Fluidized bed combustion, 0210 nano-technology, business, Process engineering, Génie des procédés, Solar power
Abstract

Electricity from concentrated solar power (CSP) plants, gains an increasing interest and importance. To fully match the supply-demand principle, CSP processes include a thermal energy storage and back-up fuel supply. Novel CSP concepts are needed with specific targets of increased efficiency and reliability, and of reduced CAPEX and OPEX. The use of particle suspensions offers significant advantages since applicable in all sub-sections of the complete CSP as heat carrier from the receiver, to the heat storage, and ultimately to the power block. The use of particles in the steam generation (power block) is a common fluidized bed boiler technology. This paper will present the entire particle-based concept, while also discussing the potential to use biomass-based energy carriers as back-up heat supply. Process data and expected effects on the process economy of the system will be discussed.

Published
2020

6. Dépliage de Boucles Versus Précision Numérique

Author

Damouche, Nasrine, Thirioux, Xavier, Benmaghnia, Hanane, Martel, Matthieu, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université Toulouse - Jean Jaurès - UT2J (FRANCE), Université Toulouse 1 Capitole - UT1 (FRANCE), and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
Dépliage de boucles, Autre, Analyse statique, Interprétation abstraite, Précision numérique, Erreurs d'arrondis
Abstract

Les calculs en nombres flottants sont intensivement utilisés dans divers domaines, notamment les systèmes embarqués critiques. En général, les résultats de ces calculs sont perturbés par les erreurs d’arrondi. Dans un scenario critique, ces erreurs peuvent être accumulées et propagées, générant ainsi des dommages plus ou moins graves sur le plan humain, matériel, financier, etc. Il est donc souhaitable d’obtenir les résultats les plus précis possibles lorsque nous utilisons l’arithmétique flottante. Pour remédier à ce problème, l’outil Salsa [7] permet d’améliorer la précision des calculs en corrigeant partiellement ces erreurs d’arrondi par une transformation automatique et source à source des programmes. La principale contribution de ce travail consiste à analyser, à étudier si l’optimisation par dépliage de boucles améliore plus la précision numérique des calculs dans le programme initial. À cours terme, on souhaite définir un facteur de dépliage de boucles, c’est à dire, trouver quand est-ce qu’il est pertinent de déplier la boucle dans le programme.

Published
2019

7. Activated-carbon/TiO2 composites preparation: An original grafting by milling approach for solar water treatment applications

Author

Francis Teyssandier, Gael Plantard, Vincent Goetz, Enrique Ribeiro, Najim Sadiki, Francis Maury, Denis Chaumont, Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Laboratoire Interdisciplinaire Carnot de Bourgogne [Dijon] (LICB), Université de Bourgogne (UB)-Université de Technologie de Belfort-Montbeliard (UTBM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université de Bourgogne - UB (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Technologie de Belfort-Montbéliard - UTBM (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Laboratoire Interdisciplinaire Carnot de Bourgogne (LICB), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Institut De Science Et De Génie Des Matériaux Et Procédés (IMP-CNRS), and Université de Perpignan Via Domitia (UPVD)

Subjects
Materials science, Matériaux, 02 engineering and technology, 010402 general chemistry, composites, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, [SPI]Engineering Sciences [physics], Crystallinity, Adsorption, medicine, Chemical Engineering (miscellaneous), Water treatment, Photocatalysis, mechanosynthesis, Composite material, Photodegradation, Waste Management and Disposal, ComputingMilieux_MISCELLANEOUS, Composites, [SDE.IE]Environmental Sciences/Environmental Engineering, Process Chemistry and Technology, water treatment, [CHIM.MATE]Chemical Sciences/Material chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, Microporous material, 021001 nanoscience & nanotechnology, Pollution, 6. Clean water, 0104 chemical sciences, adsorption, 13. Climate action, Mechanosynthesis, Absorption (chemistry), 0210 nano-technology, photocatalysis, Activated carbon, medicine.drug
Abstract

International audience; The aim of this work was to highlight feasibility of a new approach to synthesize Activated-Carbon (AC)/TiO2 composite materials. The main interest of these materials is for pollutants removal applications thanks to their multi-functionality. AC/TiO2 composites were prepared by one-step mechanosynthesis route. Morphological and structural properties were investigated through SEM, EDS, XRD, and BET techniques. It was found that the preparation process leads to the formation of an aggregate shape homogenously composed AC/TiO2 powder with a narrow particles size distribution, which mean diameter was 3.75 μm. Initial component structural properties were found to be strongly affected by the process, resulting in significant changes of TiO2 crystallinity and AC microtexture. The introduction of 5 min pauses during the process was enough to totally preserve TiO2 phases, crystallinity, and AC microporous network. Composites multi-functional properties were investigated using batch adsorption and photodegradation experiments. Adsorption studies revealed that AC/TiO2 aggregates exhibit good adsorption capacity with caffeine and a maximum adsorbed amount of 353 mg.g−1. Photocatalytic experiments highlighted that AC/TiO2 presents a photo-oxidation ability. Photodegradation apparent kinetic rate fitted with a first-order law gave a value of 1.04 × 10-5 s-1 for the composite and ten times higher for pure TiO2. These results allowed to conclude that mechanosynthesis is an effective route to produce bi-functional AC/TiO2 composites with efficient adsorption capacity for water treatment applications. It also suggests the need of further radiative transfer studies to understand light scattering and absorption inside these materials, which could lead to some improvement of these promising materials.

Published
2020

8. Improving the Numerical Accuracy of High Performance Computing Programs by Process Specialization

Author

Matthieu Martel, Farah Benmouhoub, Nasrine Damouche, and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
Execution time, Autre, Process (engineering), Computer science, Specialization (functional), Program transformation based semantic, Numerical accuracy, Foating-point arithmetic, High performance computing, Supercomputer, Industrial engineering
Abstract

In high performance computing, nearly all the implementations and published experiments use floating-point arithmetic. However, since floating-point numbers are finite approximations of real numbers, it may result in hazards because of the accumulated errors. These round-off errors may cause damages whose gravity varies depending on the critical level of the application. To deal with this issue, we have developed a tool which im- proves the numerical accuracy of computations by automatically transforming programs in a source-to-source manner. Our transformation, relies on static analysis by abstract interpretation and operates on pieces of code with assignments, conditionals, loops, functions and arrays. In this article, we apply our techniques to optimize a parallel program representative of the high performance computing domain. Parallelism introduces new numerical accuracy problems due to the order of operations in this kind of systems. We are also interested in studying the compromise between execution time and numerical accuracy.

Published
2018

9. Utility network optimization in eco-industrial parks by a multi-leader follower game methodology

Author

Serge Domenech, Didier Aussel, Ludovic Montastruc, Marianne Boix, Mariona Rocafull, Manuel A. Ramos, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Procédés, Matériaux et Energie Solaire (PROMES), and Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Operations research, Computer science, 020209 energy, General Chemical Engineering, 02 engineering and technology, Multi-objective optimization, Nash equilibrium, symbols.namesake, Process simulation, [CHIM.GENI]Chemical Sciences/Chemical engineering, 020401 chemical engineering, Order (exchange), 0202 electrical engineering, electronic engineering, information engineering, Stackelberg competition, Génie chimique, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, 0204 chemical engineering, Génie des procédés, Utility network, Game theory, Consumption (economics), Multi-leader-follower game, Computer Science Applications, Eco-industrial parks, symbols, MPCC
Abstract

International audience; A multi-leader-follower game (MLFG) model for the design of the utility network in an eco-industrial park (EIP) is studied and implemented by introducing the concept of an environmental authority. The methodology also considers the flowsheet simulation of each enterprise involved in the EIP in order to obtain utility consumption of each enterprise operating by itself. The approach is validated on a case study of a potential Norwegian EIP. In the latter, multi-leader-single-follower and single-leader-multi-follower game models are studied. Each enterprise's objective is to minimize the total annualized cost, while the EIP authority objective is to minimize the equivalent CO2 consumption related to utility consumption within the ecopark. The MLFG is transformed into a MOPEC and solved using GAMS® as an NLP. The methodology proposed is proven to be reliable in multi-criteria scenarios compared to traditional multiobjective optimization approaches, providing numerical Nash/Stackelberg equilibrium solutions and specifically in EIP planning and optimization.

Published
2018

10. On the Impact of Numerical Accuracy Optimization on General Performances of Programs

Author

Matthieu Martel, Nasrine Damouche, and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
Semantics (computer science), Computer science, Numerical analysis, Abstract interpretation, Floating-point arithmetic, 020207 software engineering, 02 engineering and technology, Code size, Static analysis, Accuracy improvement, Execution time, Transformation (function), Autre, Optimization of performances, 0202 electrical engineering, electronic engineering, information engineering, Computer Science::Programming Languages, 020201 artificial intelligence & image processing, Algorithm, Real number
Abstract

The floating-point numbers used in computer programs are a finite approximation of real numbers. In practice, this approximation may introduce round-off errors and this can lead to catastrophic results. In previous work, we have proposed intraprocedural and interprocedural program transformations for numerical accuracy optimization. All these transformations have been implemented in our tool, Salsa. The experimental results applied on various programs either coming from embedded systems or numerical methods, show the efficiency of the transformation in terms of numerical accuracy improvement but also in terms of other criteria such as execution time and code size. This article studies the impact of program transformations for numerical accuracy specially in embedded systems on other efficiency parameters such as execution time, code size and accuracy of the other variables (these which are not chosen for optimization).

Published
2018

11. Pharmaceuticals released from senior residences: occurrence and risk evaluation

Author

Sílvia Luís, Silvia Lacorte, Juan Ignacio Aragonés, Ana Maria Oliveira-Brett, Cristian Gómez-Canela, Claire Joannis-Cassan, Carole Calas-Blanchard, Lucía Poggio, Thierry Noguer, Teresa Sala-Comorera, Luisa Lima, Benoit Roig, Carlos Barata, Audrey Courtier, Institute of Environmental Assessment and Water Research (IDAEA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Centro de Investigação e Intervenção Social (CIS), Instituto Universitário de Lisboa (ISCTE-IUL), Détection, évaluation, gestion des risques CHROniques et éMErgents (CHROME) / Université de Nîmes (CHROME), Université de Nîmes (UNIMES), Universidade de Coimbra [Coimbra], Laboratoire de Génie Chimique (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Facultad de Psicología, Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Biocapteurs-Analyses-Environnement (BAE), Université de Perpignan Via Domitia (UPVD), Centre National de la Recherche Scientifique - CNRS (FRANCE), Consejo Superior de Investigaciones Científicas - CSIC (SPAIN), Universidade de Coimbra (PORTUGAL), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Instituto Universitario de Lisboa - ISCTE IUL (PORTUGAL), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Universidad Complutense de Madrid - UCM (SPAIN), Université de Nîmes (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Détection, évaluation, gestion des risques CHROniques et éMErgents - CHROME (Nimes, France), Laboratoire de Génie Chimique - LGC (Toulouse, France), Biocapteurs Analyse Environnement - BAE (Perpignan, France), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Laboratoire de Biodiversité et Biotechnologies Microbiennes (LBBM), PIERRE FABRE-EDF (EDF)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Institut National Polytechnique de Toulouse - INPT (FRANCE)

Subjects
010504 meteorology & atmospheric sciences, Health, Toxicology and Mutagenesis, Environmental pollution, Wastewater, 010501 environmental sciences, Risk Assessment, 01 natural sciences, Rivers, Environmental health, Sewerage, Health care institutions, Homes for the Aged, Humans, Environmental Chemistry, Génie chimique, Génie des procédés, Effluent, Antidiabetic agents, Aged, 0105 earth and related environmental sciences, Portugal, Environmental engineering, Predicted environmental concentrations, General Medicine, Pollution, 6. Clean water, 3. Good health, Risk evaluation, Pharmaceutical Preparations, Risk management, Spain, 13. Climate action, [SDE]Environmental Sciences, Environmental science, Pharmaceuticals, Sewage treatment, France, Housing for the Elderly, Ciências Naturais::Ciências da Terra e do Ambiente [Domínio/Área Científica], Water Pollutants, Chemical, Environmental Monitoring
Abstract

One of the main pursuits, yet most difficult, in monitoring studies is to identify the sources of environmental pollution. In this study, we have identified health-care facilities from south European countries as an important source of pharmaceuticals in the environment. We have estimated that compounds consumed in by the elderly and released from effluents of senior residences can reach river waters at a concentration higher than 0.01 ?g/L, which is the European Medicines Agency (EMA) threshold for risk evaluation of pharmaceuticals in surface waters. This study has been based on five health institutions in Portugal, Spain, and France, with 52 to 130 beds. We have compiled the pharmaceuticals dispensed on a daily base and calculated the consumption rates. From 54.9 to 1801 g of pharmaceuticals are consumed daily, with laxatives, analgesics, antiepileptics, antibiotics, and antidiabetic agents being the main drug families administered. According to excretion rates, dilution in the sewerage system, and elimination in wastewater treatment plants, macrogol, metformin, paracetamol, acetylcysteine, amoxicillin, and gabapentin, among others, are expected to reach river waters. Finally, we discuss the risk management actions related to the discharge of pharmaceuticals from senior residences to surface waters. info:eu-repo/semantics/acceptedVersion

Published
2018

12. Three-dimensional Numerical Simulation of Upflow BubblingFluidized Bed in Opaque Tube Under High Flux Solar Heating

Author

Gilles Flamant, Hadrien Benoit, Hervé Neau, Renaud Ansart, Olivier Simonin, Pablo García-Triñanes, Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Institut de mécanique des fluides de Toulouse (IMFT), University of Greenwich, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), University of Greenwich (UNITED KINGDOM), Université de Perpignan Via Domitia - UPVD (FRANCE), Institut de Mécanique des Fluides de Toulouse - IMFT (Toulouse, France), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université Toulouse III - Paul Sabatier - UPS (FRANCE), Laboratoire Procédés, Matériaux et Energie Solaire - PROMES (Perpignan, France), and Laboratoire de Génie Chimique - LGC (Toulouse, France)

Subjects
Convection, Environmental Engineering, Materials science, General Chemical Engineering, Mécanique des fluides, Gas–particle flow, 3D numerical simulation, 02 engineering and technology, Heat transfer coefficient, 7. Clean energy, Physics::Fluid Dynamics, 020401 chemical engineering, Concentrated solar power, Radiative transfer, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], 0204 chemical engineering, Euler–euler model, heat transfer fluid, Multiphase flow, Mechanics, 021001 nanoscience & nanotechnology, Heat flux, Particle solar receiver, Heat transfer, Particle, 0210 nano-technology, Biotechnology
Abstract

International audience; Solid particles can be used as a heat transfer medium in concentrated solar power plants to operate at higher temperature and achieve higher heat conversion efficiency than using the current solar heat transfer fluids that only work below 600°C. Among various particle circulation concepts, the dense particle suspension (DPS) flow in tubes, also called upflow bubbling fluidized bed (UBFB), was studied in the frame of the CSP2 FP7 European project. The DPS capacity to extract heat from a tube absorber exposed to concentrated solar radiation was demonstrated and the first values of the tube wall-to-DPS heat transfer coefficient were measured. A stable outlet temperature of 750°C was reached with a metallic tube, and a particle reflux in the near tube wall region was evidenced. In this article, the UBFB behavior is studied using the multiphase flow code NEPTUNE_CFD. Hydrodynamics of SiC Geldart A-type particles and heat transfer imposed by a thermal flux at the wall are coupled in two-dimensional unsteady numerical simulations. The convective/diffusive heat transfer between the gas and dispersed phase, and the inter-particle radiative transfer (Rosseland approximation) are accounted for. Simulations and experiments are compared here and the temperature influence on the DPS flow is analyzed.

Published
2018

13. Numerical program optimisation by automatic improvement of the accuracy of computations

Author

Matthieu Martel, Nasrine Damouche, Alexandre Chapoutot, Ecole Nationale Supérieure de Techniques Avancées - ENSTA (FRANCE), Université Paris-Saclay (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), LAboratoire de Mathématiques et PhySique (LAMPS), Université de Perpignan Via Domitia (UPVD), Sûreté et Fiabilité des Logiciels (SFL), Unité d'Informatique et d'Ingénierie des Systèmes (U2IS), and École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)

Subjects
Floating point, Convergence Acceleration, Iterative method, Computer science, Floating-Point Numbers, [INFO.INFO-DS]Computer Science [cs]/Data Structures and Algorithms [cs.DS], Program transformation, Double-precision floating-point format, Static analysis, [INFO.INFO-NA]Computer Science [cs]/Numerical Analysis [cs.NA], Single-precision floating-point format, [INFO.INFO-CL]Computer Science [cs]/Computation and Language [cs.CL], Program Transformation, Data-Types Format Optimization, Transformation (function), IEEE754 Standard, Autre, Algorithm, Abstraction (linguistics)
Abstract

International audience; Over the last decade, guaranteeing the accuracy of computations relying on the IEEE754 floating-point arithmetic has become increasingly complex. Failures, caused by small or large perturbations due to round-off errors, have been registered. To cope with this issue, we have developed a tool which corrects these errors by automatically transforming programs in a source to source manner. Our transformation, relying on static analysis by abstract abstraction, operates on pieces of code with assignments, conditionals and loops. By transforming programs, we can significantly optimise the numerical accuracy of computations by minimising the error relatively to the exact result. In this article, we present two important desirable side-effects of our transformation. Firstly, we show that our transformed programs, executed in single precision, may compete with not transformed codes executed in double precision. Secondly, we show that optimising the numerical accuracy of programs accelerates the convergence of numerical iterative methods. Both of these properties of our transformation are of great interest for numerical software.

Published
2018

14. Mixed Precision Tuning with Salsa

Author

Nasrine Damouche, Matthieu Martel, and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
060201 languages & linguistics, Computer science, Mixed Precision, Numerical Accuracy, 06 humanities and the arts, 02 engineering and technology, Mixed precision, Computational science, Program Transformation, Autre, 0602 languages and literature, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Floating-point Arithmetic, computer, SALSA, computer.programming_language
Abstract

Precision tuning consists of finding the least floating-point formats enabling a program to compute some results with an accuracy requirement. In mixed precision, this problem has a huge combinatory since any value may have its own format. Precision tuning has given rise to the development of several tools that aim at guarantying a desired precision on the outputs of programs doing floating-point computations, by minimizing the initial, over-estimated, precision of the inputs and intermediary results. In this article, we present an extension of our tool for numerical accuracy, Salsa, which performs precision tuning. Originally, Salsa is a program transformation tool based on static analysis and which improves the accuracy of floating-point computations. We have extended Salsa with a precision tuning static analysis. We present experimental results showing the efficiency of this new feature as well as the additional gains that we obtain by performing Salsa’s program transformation before the precision tuning analysis. We experiment our tool on a set of programs coming from various domains like embedded systems and numerical analysis.

Published
2018

15. Experimental hydrodynamic study of gas-particle dense suspension upward flow for application as new heat transfer and storage fluid

Author

Daniel J. Gauthier, Mehrdji Hemati, Benjamin Boissière, Gilles Flamant, Renaud Ansart, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Procédés, Matériaux et Energie Solaire (PROMES), and Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Heat transfer media, 020209 energy, General Chemical Engineering, Upward flow, Mechanical engineering, 02 engineering and technology, 7. Clean energy, [CHIM.GENI]Chemical Sciences/Chemical engineering, 0202 electrical engineering, electronic engineering, information engineering, Génie chimique, Fluidization, Fluidized bed combustion, Porosity, Dense particle suspension, Pressure drop, Mechanics, 021001 nanoscience & nanotechnology, Fine particles (A/B‐type), [SPI.MECA.GEME]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanical engineering [physics.class-ph], Volumetric flow rate, Fluidized bed, Génie mécanique, Heat transfer, 0210 nano-technology, Secondary air injection
Abstract

International audience; This paper focuses on a new concept of Heat Transfer Fluid (HTF) for Concentrating Solar Plants (CSP) applications through fluidized bed. CSP plants with very high concentration (such as solar tower plant technology) offer good efficiencies because of high operating temperatures. CSP efficiency could be greatly increased through more efficient HTF. Molten salts, mineral oils, water and air have some of the following drawbacks: limited range of operating temperatures, corrosiveness, high pressure, low energy storage capacity and toxicity.To replace classical HTF, Dense Particle Suspension (DPS) fluidized with air (approximately 40% of solid) is proposed. DPS has a volume heat capacity similar to those of liquid HTF, does not need pressurization, is safe, inert and is only limited by the maximal working temperature of the receiver material (1100 K), thus opening new opportunities for high efficiency thermodynamic cycles. This work is the hydrodynamic study of a gassolid dense suspension upward flow at ambient temperature, in a vertical 2‐tube bundle of small diameter tubes, which have their bottom immersed in a slightly pressurized fluidized bed (pressure approximately equal to the ratio of the solid weight in a tube over its cross section area). This type of flow is yet implemented in the field of hyper‐dense phase vertical conveying of powders and it is currently under development for solar receivers using dense suspensions of particles as heat transfer and storage medium. This application was patented by Flamant and Hemati in 2010 (France 1058565 (2010) CNRS/INP Toulouse, G. Flamant, H. Hemati; PCT Extension, No. WO 2012/052661 A2), and its development is funded by the European Commission. In this technological breakthrough, the concentrated solar energy is collected, carried and stored directly by the fine particles flowing upward, with a suspension void fraction close to that of a dense fluidized bed. Contrary to circulating fluidized bed “risers”, it offers a good contact area between the wall and the particles. The important hydrodynamic and thermal coupling required a step‐by‐step approach. Ambient flows had to be understood and controlled first. Thus a 2‐pass “cold” mock‐up, each pass composed of two vertical parallel tubes, was built. Pressure drop, solid weight and helium volume fraction measurements demonstrated the ability to handle a regular solid upward flow (imperative here), with solid flow rates from 20 to 130 kg/h, with void fractions from 0.57 to 0.63 and with an even distribution of the solid flow rate between the tubes. Moreover, the governing parameters of this flow were established as: the solid feeding flow rate, the fluidization velocity, the solid holdup, the freeboard pressure and the aeration velocity. The secondary air injection, also called “aeration”, is the most important parameter for the stability and the even distribution of the total solid flow rate in the tubes. The 1D modelling of the suspension flow in the tubes was also performed in the flow direction. The flow structure was described using the bubble‐emulsion model formalism, and by adding the solid entrainment by the bubble wake. Predictions of the model are compared with the experimental measurements of driving pressure and axial pressure profile along the tubes.

Published
2014

16. A Distant Learning Approach for Extracting Hypernym Relations from Wikipedia Disambiguation Pages

Author

Cécile Fabre, Nathalie Aussenac-Gilles, Adel Ghamnia, Cassia Trojahn, Mouna Kamel, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université Toulouse - Jean Jaurès - UT2J (FRANCE), Université Toulouse 1 Capitole - UT1 (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Institut de Recherche en Informatique de Toulouse - IRIT (Toulouse, France), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université de Perpignan Via Domitia (UPVD), MEthodes et ingénierie des Langues, des Ontologies et du DIscours (IRIT-MELODI), Institut de recherche en informatique de Toulouse (IRIT), Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Université Toulouse - Jean Jaurès (UT2J), Centre National de la Recherche Scientifique (CNRS), Cognition, Langues, Langage, Ergonomie (CLLE-LTC), École pratique des hautes études (EPHE), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Toulouse - Jean Jaurès (UT2J)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Relation (database), Process (engineering), Computer science, Hypernym relation, 02 engineering and technology, computer.software_genre, [INFO.INFO-CL]Computer Science [cs]/Computation and Language [cs.CL], [INFO.INFO-AI]Computer Science [cs]/Artificial Intelligence [cs.AI], Domain (software engineering), Knowledge extraction, [INFO.INFO-LG]Computer Science [cs]/Machine Learning [cs.LG], Fragment (logic), Distant learning, 020204 information systems, 0202 electrical engineering, electronic engineering, information engineering, Pattern matching, General Environmental Science, Logique en informatique, Information retrieval, Knowledge bases, business.industry, Supervised learning, [INFO.INFO-LO]Computer Science [cs]/Logic in Computer Science [cs.LO], Informatique et langage, Intelligence artificielle, Variety (linguistics), Apprentissage, Key (cryptography), General Earth and Planetary Sciences, 020201 artificial intelligence & image processing, Artificial intelligence, business, computer, Natural language processing, Wikipedia
Abstract

International audience; Extracting hypernym relations from text is one of the key steps in the automated construction and enrichment of semantic resources. The state of the art offers a large varierty of methods (linguistic, statistical, learning based, hybrid). This variety could be an answer to the need to process each corpus or text fragment according to its specificities (e.g. domain granularity, nature, language, or target semantic resource). Moreover, hypernym relation may take different linguistic forms. The aim of this paper is to study the behaviour of a supervised learning approach to extract hypernym relations whatever the way they are expressed, and to evaluate its ability to capture regularities from the corpus, without human intervention. We apply a distant supervised learning algorithm on a sub-set of Wikipedia in French made of disambiguation pages where we manually annotated hypernym relations. The learned model obtained a F-measure of 0.67, outperforming lexico-syntactic pattern matching used as baseline.

Published
2017

17. High-temperature thermochemical energy storage based on redox reactions using Co-Fe and Mn-Fe mixed metal oxides

Author

Laurent Cassayre, Laurie André, Stéphane Abanades, Institut De Science Et De Génie Des Matériaux Et Procédés (IMP-CNRS), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
Solid-gas reaction, 020209 energy, Inorganic chemistry, Iron oxide, 02 engineering and technology, engineering.material, Bixbyite, 7. Clean energy, Redox, Inorganic Chemistry, Metal, Reaction rate, chemistry.chemical_compound, Transition metal, Thermodynamic equilibrium calculations, Oxidation, 0202 electrical engineering, electronic engineering, information engineering, Materials Chemistry, Génie chimique, Physical and Theoretical Chemistry, Cobalt oxide, Reduction, Metal oxide, Spinel, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, chemistry, visual_art, Ceramics and Composites, visual_art.visual_art_medium, engineering, 0210 nano-technology, Thermal heat storage
Abstract

International audience; Metal oxides are potential materials for thermochemical heat storage via reversible endothermal/exothermal redox reactions, and among them, cobalt oxide and manganese oxide are attracting attention. The synthesis of mixed oxides is considered as a way to answer the drawbacks of pure metal oxides, such as slow reaction kinetics, loss-in-capacity over cycles or sintering issues, and the materials potential for thermochemical heat storage application needs to be assessed. This work proposes a study combining thermodynamic calculations and experimental measurements by simultaneous thermogravimetric analysis and calorimetry, in order to identify the impact of iron oxide addition to Co and Mn-based oxides. Fe addition decreased the redox activity and energy storage capacity of Co3O4/CoO, whereas the reaction rate, reversibility and cycling stability of Mn2O3/Mn3O4 was significantly enhanced with added Fe amounts above ~15 mol%, and the energy storage capacity was slightly improved. The formation of a reactive cubic spinel explained the improved re-oxidation yield of Mn-based oxides that could be cycled between bixbyite and cubic spinel phases, whereas a low reactive tetragonal spinel phase showing poor re-oxidation was formed below 15 mol% Fe. Thermodynamic equilibrium calculations predict accurately the behavior of both systems. The possibility to identify other suitable mixed oxides becomes conceivable, by enabling the selection of transition metal additives for tuning the redox properties of mixed metal oxides destined for thermochemical energy storage applications.

Published
2017

18. Improving the numerical accuracy of programs by automatic transformation

Author

Alexandre Chapoutot, Nasrine Damouche, Matthieu Martel, Ecole Nationale Supérieure de Techniques Avancées - ENSTA (FRANCE), Université Paris-Saclay (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), LAboratoire de Mathématiques et PhySique (LAMPS), Université de Perpignan Via Domitia (UPVD), Sûreté et Fiabilité des Logiciels (SFL), Unité d'Informatique et d'Ingénierie des Systèmes (U2IS), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris), and ANR-12-INSE-0007,CAFEIN,Combinaison d'approches formelles pour l'étude d'invariants numériques(2012)

Subjects
Floating point, Computer science, [INFO.INFO-AO]Computer Science [cs]/Computer Arithmetic, [INFO.INFO-DS]Computer Science [cs]/Data Structures and Algorithms [cs.DS], Program transformation, 020207 software engineering, 02 engineering and technology, Static analysis, Abstract interpretation, [INFO.INFO-CL]Computer Science [cs]/Computation and Language [cs.CL], IEEE754 standard, Transformation (function), Autre, Theory of computation, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Numerical accuracy, Sensitivity (control systems), Time complexity, Algorithm, Floating-point numbers, Software, Information Systems
Abstract

International audience; he dangers of programs performing floating- point computations are well known. This is due to the sensitivity of the results to the way formulæ are written. These last years, several techniques have been proposed concerning the transformation of arithmetic expressions in order to improve their numerical accuracy and, in this arti- cle, we go one step further by automatically transforming larger pieces of code containing assignments and control structures. We define a set of transformation rules allowing the generation, under certain conditions and in polynomial time, of larger expressions by performing limited formal computations, possibly among several iterations of a loop. These larger expressions are better suited to improve, by reparsing, the numerical accuracy of the program results. We use abstract interpretation-based static analysis techniques to over-approximate the round-off errors in programs and during the transformation of expressions. A tool has been implemented and experimental results are presented con- cerning classical numerical algorithms and algorithms for embedded systems.

Published
2017

19. Numerical Accuracy Improvement by Interprocedural Program Transformation

Author

Alexandre Chapoutot, Nasrine Damouche, Matthieu Martel, LAboratoire de Mathématiques et PhySique (LAMPS), Université de Perpignan Via Domitia (UPVD), Sûreté et Fiabilité des Logiciels (SFL), Unité d'Informatique et d'Ingénierie des Systèmes (U2IS), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris), Ecole Nationale Supérieure de Techniques Avancées - ENSTA (FRANCE), Université Paris-Saclay (FRANCE), and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
Floating point, [INFO.INFO-PL]Computer Science [cs]/Programming Languages [cs.PL], Computer science, [INFO.INFO-DS]Computer Science [cs]/Data Structures and Algorithms [cs.DS], Program transformation, 020207 software engineering, Floating-point arithmetic, 02 engineering and technology, Parallel computing, Static analysis, Abstract interpretation, Range (mathematics), Embedded software, Transformation (function), Autre, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Numerical accuracy, Algorithm, Interprocedural program transformation, Real number
Abstract

International audience; Floating-point numbers are used to approximate the exact real numbers in a wide range of domains like numerical simulations, embedded software, etc. However, floating-point numbers are a finite approximation of real numbers. In practice, this approximation may introduce round-off errors and this can lead to catastrophic results. To cope with this issue, we have developed a tool which corrects partly these round-off errors and which consequently improves the numerical accuracy of computations by automatically transforming programs in a source to source manner. Our transformation, relies on static analysis by abstract interpretation and operates on pieces of code with assignments, conditionals and loops. In former work, we have focused on the intraprocedural transformation of programs and, in this article, we introduce the interprocedural transformation to improve accuracy.

Published
2017

20. Salsa: An Automatic Tool to Improve the Numerical Accuracy of Programs

Author

Nasrine Damouche, Matthieu Martel, and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
business.industry, Computer science, Floating-point arithmetic, 02 engineering and technology, Machine learning, computer.software_genre, Static analysis, 01 natural sciences, 010305 fluids & plasmas, Automatic transformation of programs, Autre, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Numerical accuracy, Artificial intelligence, business, computer, SALSA, computer.programming_language
Abstract

This article describes Salsa, an automatic tool to improve the accuracy of the floating- point computations done in numerical codes. Based on static analysis methods by abstract interpretation, our tool takes as input an original program, applies to it a set of transformations and then generates an optimized program which is more accurate than the initial one. The original and the transformed programs are written in the same imperative language. This article is a concise description of former work on the techniques implemented in Salsa, extended with a presentation of the main software architecture, the inputs and outputs of the tool as well as experimental results obtained by applying our tool on a set of sample programs coming from embedded systems and numerical analysis.

Published
2017

21. Experimental and thermodynamic study of Co-Fe and Mn-Fe based mixed metal oxides for thermochemical energy storage application

Author

Stéphane Abanades, Laurent Cassayre, Laurie André, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
Work (thermodynamics), 020209 energy, Inorganic chemistry, Iron oxide, Sintering, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, 021001 nanoscience & nanotechnology, Thermal energy storage, 7. Clean energy, Energy storage, Metal, chemistry.chemical_compound, chemistry, Transition metal, visual_art, Solar Energy, 0202 electrical engineering, electronic engineering, information engineering, visual_art.visual_art_medium, Génie chimique, Génie des procédés, 0210 nano-technology, Cobalt oxide
Abstract

International audience; Metal oxides are potential materials for thermochemical heat storage, and among them, cobalt oxide and manganese oxide are attracting attention. Furthermore, studies on mixed oxides are ongoing, as the synthesis of mixed oxides could be a way to answer the drawbacks of pure metal oxides, such as slow reaction kinetics, loss-in-capacity over cycles or sintering, selected for thermochemical heat storage application. The addition of iron oxide is under investigation and the obtained results are presented. This work proposes a comparison of thermodynamic modelling with experimental data in order to identify the impact of iron oxide addition to cobalt oxide and manganese oxide. Fe addition decreased the redox activity and energy storage capacity of Co3O4, whereas the cycling stability of Mn2O3 was significantly improved with added Fe amounts above 20 mol% while the energy storage capacity was unchanged. The thermodynamic modelling method to predict the behavior of the Mn-Fe-O and Co-Fe-O systems was validated, and the possibility to identify other mixed oxides becomes conceivable, by enabling the selection of transition metals additives for metal oxides destined for thermochemical energy storage applications.

Published
2017

22. Impact of pH on the Stability and the Cross-Reactivity of Ochratoxin A and Citrinin

Author

Jean-Louis Marty, Ingrid Bazin, Virginie Faucet-Marquis, Marie-Carmen Monje, Annie Pfohl-Leszkowicz, Micheline El Khoury, ANABIOTOX (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), IMT Mines Alès (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Laboratoire de Génie Chimique - LGC (Toulouse, France), Institut de Modélisation et d'Analyses en Géo-environnement et Santé - IMAGES Espace Dev (Perpignan, France), Laboratoire de Génie de l'Environnement Industriel (LGEI), IMT - MINES ALES (IMT - MINES ALES), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Institut de Modélisation et d'Analyses en géo-environnement et santé - Espace Développement (IMAGES-Espace DEV), UMR 228 Espace-Dev, Espace pour le développement, Université de Guyane (UG)-Université des Antilles (UA)-Institut de Recherche pour le Développement (IRD)-Université de Perpignan Via Domitia (UPVD)-Avignon Université (AU)-Université de La Réunion (UR)-Université de Montpellier (UM)-Université de Guyane (UG)-Université des Antilles (UA)-Institut de Recherche pour le Développement (IRD)-Université de Perpignan Via Domitia (UPVD)-Avignon Université (AU)-Université de La Réunion (UR)-Université de Montpellier (UM), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut de Recherche pour le Développement (IRD)-Université de Perpignan Via Domitia (UPVD)-Avignon Université (AU)-Université de La Réunion (UR)-Université de Montpellier (UM)-Université de Guyane (UG)-Université des Antilles (UA)-Institut de Recherche pour le Développement (IRD)-Université de Perpignan Via Domitia (UPVD)-Avignon Université (AU)-Université de La Réunion (UR)-Université de Montpellier (UM)-Université de Guyane (UG)-Université des Antilles (UA), Laboratoire de Génie Chimique (LGC), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université de Toulouse (UT)

Subjects
ochratoxin, Ochratoxin A, analysis, Health, Toxicology and Mutagenesis, lcsh:Medicine, Wine, Immunoaffinity, Toxicology, 01 natural sciences, Chromatography, Affinity, Ochratoxins, Polyethylene Glycols, mycotoxin, chemistry.chemical_compound, [CHIM.GENI]Chemical Sciences/Chemical engineering, wheat, Chromatography, High Pressure Liquid, Triticum, Mycotoxin, 0303 health sciences, Chemistry, Povidone, food and beverages, Hydrogen-Ion Concentration, Wheat, Acetonitriles, citrinin, immunoaffinity, wine, Food Contamination, Article, 03 medical and health sciences, Génie chimique, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Génie des procédés, Ochratoxin, 030304 developmental biology, Chromatography, lcsh:R, 010401 analytical chemistry, Extraction (chemistry), Citrinin, 0104 chemical sciences, Sodium Bicarbonate, Analysis, Food contaminant
Abstract

International audience; Mycotoxins are secondary metabolites produced by several fungi contaminating crops. In several countries, the maximum permitted levels of mycotoxins are found in foodstuffs and feedstuffs. The common strategy of mycotoxin analysis involves extraction, clean-up and quantification by chromatography. In this paper, we analyzed the reasons of underestimation of ochratoxin A (OTA) content in wine, and overestimation of OTA in wheat, depending on the pH of the clean-up step and the simultaneous presence of citrinin (CIT). We demonstrated that the increase of pH by adding polyethylene glycol (PEG) to wine led to an underestimation of OTA by conversion of OTA into open ring ochratoxin A OP-OA. In comparing three methods of extraction and clean-up for the determination of OTA and CIT in wheat—(i) an inter-laboratory validated method for OTA in cereals using immunoaffinity column clean-up (IAC) and extraction by acetonitrile/water; (ii) a validated method using IAC and extraction with 1% bicarbonate Na; and (iii) an in-house validated method based on acid liquid/liquid extraction—we observed an overestimation of OTA after immunoaffinity clean-up when CIT is also present in the sample, whereas an underestimation was observed when OTA was alone. Under neutral and alkaline conditions, CIT was partially recognized by OTA antibodies

Published
2013

23. 3D numerical simulation of upflow bubbling fluidized bed in opaque tube under high flux solar heating

Author

Benoit, Hadrien, Ansart, Renaud, Neau, Herve, García-Triñanes, Pablo, Flamant, Gilles, Simonin, Olivier, Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, University of Surrey (UNIS), Institut de mécanique des fluides de Toulouse (IMFT), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), University of Surrey (UNITED KINGDOM), Institut de Mécanique des Fluides de Toulouse - IMFT (Toulouse, France), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université Toulouse III - Paul Sabatier - UPS (FRANCE), Laboratoire Procédés, Matériaux et Energie Solaire - PROMES (Perpignan, France), and Laboratoire de Génie Chimique - LGC (Toulouse, France)

Subjects
Tubular solar receiver, Tubular solar receiver- Gas-particle flow, Mécanique des fluides, 3D numerical simulation, Heat transfer fluid, Physics::Fluid Dynamics, [CHIM.GENI]Chemical Sciences/Chemical engineering, TA, Génie chimique, Euler-euler model, Gas-particle flow, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Génie des procédés
Abstract

Solid particles can be used as a heat transfer medium in concentrated solar power plants to operate at higher temperature and achieve higher heat conversion efficiency than using the current solar Heat Transfer Fluids (HTF) that only work below 600 ◦C. Among various particle circulation concepts, the Dense Particle Suspension (DPS) flow in tubes, also called Upflow Bubbling Fluidized Bed (UBFB), was studied in the frame of the CSP2 FP7European project. The DPS capacity to extract heat from a tube absorber exposed to concentrated solar radiation was demonstrated and the first values of the tube wall-to-DPS heat transfer coefficient were measured. A stable outlet temperature of 750 ◦C was reached with a metallic tube, and a particle reflux in the near tube wall region was evidenced. In thispaper, the UBFB behavior is studied using the multiphase flow code NEPTUNE CFD. Hydrodynamics of SiC Geldart A-type particles and heat transfer imposed by a thermal flux at the wall are coupled in 3D unsteady numerical simulations. The convective/diffusive heat transfer between the gas and dispersed phase, and the inter-particle radiative transfer (Rosseland approximation) are accounted for. Simulations and experiments are compared here and the temperature influence on the DPS flow is analyzed.

Published
2016

24. Data-types optimization for floating-point formats by program transformation

Author

Matthieu Martel, Nasrine Damouche, Alexandre Chapoutot, LAboratoire de Mathématiques et PhySique (LAMPS), Université de Perpignan Via Domitia (UPVD), Sûreté et Fiabilité des Logiciels (SFL), Unité d'Informatique et d'Ingénierie des Systèmes (U2IS), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris), ANR-12-INSE-0007,CAFEIN,Combinaison d'approches formelles pour l'étude d'invariants numériques(2012), Ecole Nationale Supérieure de Techniques Avancées - ENSTA (FRANCE), Université Paris-Saclay (FRANCE), and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
program transformation, [INFO.INFO-PL]Computer Science [cs]/Programming Languages [cs.PL], Floating point, Computer science, Floating-point computation, Program transformation, Abstract interpretation, Double-precision floating-point format, 02 engineering and technology, Static analysis, Data type, Single-precision floating-point format, Electronic mail, 020202 computer hardware & architecture, Transformation (function), Autre, 0202 electrical engineering, electronic engineering, information engineering, Data-Type optimization, Numerical accuracy, 020201 artificial intelligence & image processing, abstract interpretation, Algorithm
Abstract

International audience; In floating-point arithmetic, a desirable property of computations is to be accurate, since in many industrial context small or large perturbations due to round-off errors may cause considerable damages. To cope with this matter of facts, we have developed a tool which corrects these errors by transforming automatically programs in a source to source manner. Our transformation, relying on static analysis by abstract abstraction, concerns pieces of code with assignments, conditionals and loops. By transforming programs, we significantly optimize the numer- ical accuracy of computations by minimizing the error relatively to the exact result. An interesting side-effect of our technique is that more accurate computations may make it possible to use smaller data-types. In this article, we show that our transformed programs, executed in single precision, may compete with not transformed codes executed in double precision.

Published
2016

25. Solution Layer Deposition: A Technique for the Growth of Ultra-Pure Manganese Oxides on Silica at Room Temperature

Author

Vincent Collière, Jérôme Esvan, Eric Bêche, Pierre Fau, Yannick Coppel, Kilian Piettre, Bruno Chaudret, Jérémy Cure, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), STMicroelectronics [Tours] (ST-TOURS), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), STMicroelectronics, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut National des Sciences Appliquées de Toulouse - INSA (FRANCE), STMicroelectronics (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Laboratoire Procédés, Matériaux et Energie Solaire - PROMES (Perpignan, France), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
Silicon, Layer deposition, Matériaux, Inorganic chemistry, Oxide, chemistry.chemical_element, manganese amidinate, 02 engineering and technology, Manganese, Substrate (electronics), 010402 general chemistry, 01 natural sciences, Catalysis, chemistry.chemical_compound, Synthesis, X-ray photoelectron spectroscopy, Génie chimique, [CHIM]Chemical Sciences, High-resolution transmission electron microscopy, magic angle spinning NMR, Metal oxide layers, MgO on, 010405 organic chemistry, solution deposition, Silica, General Medicine, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Magic angle spinning NMR, 0104 chemical sciences, Amorphous solid, contamination-free, Contamination-free, chemistry, metal oxide layers, 0210 nano-technology, Solution deposition, Manganese amidinate, Layer (electronics)
Abstract

International audience; With the ever increasing miniaturization in microelectronic devices, new deposition techniques are required to form high-purity metal oxide layers. Herein, we report a liquid route to specifically produce thin and conformal amorphous manganese oxide layers on silicon substrate, which can be transformed into a manganese silicate layer. The undesired insertion of carbon into the functional layers is avoided through a solution metal–organic chemistry approach named Solution Layer Deposition (SLD). The growth of a pure manganese oxide film by SLD takes place through the decoordination of ligands from a metal–organic complex in mild conditions, and coordination of the resulting metal atoms on a silica surface. The mechanism of this chemical liquid route has been elucidated by solid-state 29Si MAS NMR, XPS, SIMS, and HRTEM.

Published
2016

26. Amélioration à la Compilation de la Précision de Programmes Numériques

Author

Damouche, Nasrine, Martel, Matthieu, Chapoutot, Alexandre, Ecole Nationale Supérieure de Techniques Avancées - ENSTA (FRANCE), and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
Autre, Analyse statique, Preuve de correction, Arithmétique des nombres flottants, Précision numérique, Transformation de programmes
Abstract

Les calculs en nombres flottants sont intensivement utilisés dans divers domaines, notamment les systèmes embarqués critiques. En général, les résultats de ces calculs sont perturbés par les erreurs d’arrondi. Dans un scenario critique, ces erreurs peuvent être accumulées et propagées, générant ainsi des dommages plus ou moins graves sur le plan humain, matériel, financier, etc. Il est donc souhaitable d’obtenir les résultats les plus précis possible lorsque nous utilisons l’arithmétique flottante. Pour ce faire, nous avons développé un outil qui corrige partiellement ces erreurs d’arrondi, par une transformation automatique et source à source des programmes. Notre transformation repose sur une analyse statique par interprétation abstraite qui fournit des intervalles pour les variables présentées dans les codes sources. Nous transformons non seulement des expressions arithmétiques mais aussi des morceaux de code avec des affectations, des boucles, des conditionnelles, des fonctions, etc. Les résultats obtenus par notre outils sont très prometteurs. Nous avons montré que nous améliorions de manière significative la précision numérique des calculs en minimisant l’erreur par rapport à l’arithmétique exacte des réels. Un autre critère très intéressant est que notre technique permet d’accélérer la vitesse de convergence de méthodes numériques itératives par amélioration de leur précision comme les méthodes de Newton, Jacobi, Gram-Schmidt, etc. Nous avons réussi à réduire le nombre d’itérations nécessaire pour converger de plusieurs dizaines de pourcents. Nous avons aussi étudié l’impact de l’optimisation de la précision sur le format des variables (en simple ou double précision). Pour ce faire, nous avons comparé deux programmes sources écrits en simple et en double précision avec celui transformé en simple précision. Les résultats obtenus montrent que le programme transformé (32 Bits) est très proche du résultat exact de celui de départ (64 Bits). Cela permet à l’utilisateur de dégrader la précision sans perdre beaucoup d’informations. D’un point de vue théorique, nous avons prouvé que les programmes générés n’ont pas forcément la même sémantique que les programmes d’origine, mais que mathématiquement, ils sont équivalents.

Published
2016

27. Numerical Accuracy Improvement of Programs: Principles and Experiments

Author

Damouche, Nasrine, Martel, Matthieu, Chapoutot, Alexandre, Ecole Nationale Supérieure de Techniques Avancées - ENSTA (FRANCE), Université Paris-Saclay (FRANCE), and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
Autre, Program transformation, Numerical accuracy, Static analysis, Floating-point numbers, IEEE754 standard
Abstract

In general, the correctness of numerical computations of programs based on floating-point arithmetic is not intuitive and developers hope to compute an accurate result without guaranty. To solve this problem, we procceed by automatic source to source transformation of programs to improve their numerical accuracy.

Published
2016

28. Toward a Standard Benchmark Format and Suite for Floating-Point Analysis

Author

Zachary Tatlock, Alex Sanchez-Stern, Chen Qiu, Pavel Panchekha, Nasrine Damouche, Matthieu Martel, University of Washington (USA), and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
Floating point, Rounding errors, Programming language, Computer science, Computation, Suite, 020207 software engineering, 02 engineering and technology, computer.software_genre, Abstract interpretation, Imperative programming, Autre, 020204 information systems, Research community, Floating-Point Benchmarks, 0202 electrical engineering, electronic engineering, information engineering, Benchmark (computing), Numerical accuracy, computer, Affine arithmetic
Abstract

We introduce FPBench, a standard benchmark format for validation and optimization of numerical accuracy in floating-point computations. FPBench is a first step toward addressing an increasing need in our community for comparisons and combinations of tools from different application domains. To this end, FPBench provides a basic floating-point benchmark format and accuracy measures for comparing different tools. The FPBench format and measures allow comparing and composing different floating-point tools. We describe the FPBench format and measures and show that FPBench expresses benchmarks from recent papers in the literature, by building an initial benchmark suite drawn from these papers. We intend for FPBench to grow into a standard benchmark suite for the members of the floating-point tools research community.

Published
2016

29. Transformation of a PID Controller for Numerical Accuracy

Author

Nasrine Damouche, Alexandre Chapoutot, Matthieu Martel, Centre National de la Recherche Scientifique - CNRS (FRANCE), Ecole Nationale Supérieure de Techniques Avancées - ENSTA (FRANCE), Université de Montpellier (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier - LIRMM (Montpellier, France), LAboratoire de Mathématiques et PhySique (LAMPS), Université de Perpignan Via Domitia (UPVD), Digits, Architectures et Logiciels Informatiques (DALI), Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier (LIRMM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université de Perpignan Via Domitia (UPVD), Sûreté et Fiabilité des Logiciels (SFL), Unité d'Informatique et d'Ingénierie des Systèmes (U2IS), and École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)

Subjects
Floating point, General Computer Science, Semantics-Based Program Transformation, Computer science, Computation, Numerical Accuracy, PID controller, Theoretical Computer Science, Validation of Numerical Programs, Floating-Point Arithmetic, Transformation (function), Autre, Code (cryptography), [INFO]Computer Science [cs], Algorithm, Computer Science(all)
Abstract

International audience; Numerical programs performing floating-point computations are very sensitive to the way formulas are written. Several techniques have been proposed concerning the transformation of expressions in order to improve their accuracy and now we aim at going a step further by automatically transforming larger pieces of code containing several assignments and control structures. This article presents a case study in this direction. We consider a PID controller and we transform its code in order to improve its accuracy. The experimental data obtained when we compare the different versions of the code (which are mathematically equivalent) show that those transformations have a significant impact on the accuracy of the computations.

Published
2015

30. Optimizing the accuracy of a rocket trajectory simulation by program transformation

Author

Matthieu Martel, Alexandre Chapoutot, Nasrine Damouche, LAboratoire de Mathématiques et PhySique (LAMPS), Université de Perpignan Via Domitia (UPVD), Digits, Architectures et Logiciels Informatiques (DALI), Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier (LIRMM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université de Perpignan Via Domitia (UPVD), Sûreté et Fiabilité des Logiciels (SFL), Unité d'Informatique et d'Ingénierie des Systèmes (U2IS), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris), Ecole Nationale Supérieure de Techniques Avancées - ENSTA (FRANCE), and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
Numerical Analysis, Program Analysis, [INFO.INFO-PL]Computer Science [cs]/Programming Languages [cs.PL], Floating point, Computer simulation, Computer science, Floating-Point Numbers, Abstract Interpretation, Optimizing compiler, Program transformation, Parallel computing, Static analysis, 16. Peace & justice, Abstract interpretation, Program Transformation, Semantics of Programming Languages, Autre, Computer Arithmetic, Rewriting, Sensitivity (control systems), Compiler Op- timizations, Algorithm, Accuracy
Abstract

International audience; Static analysis by abstract interpretation is one of the most successful techniques used to over-approximate the roundoff errors in numerical programs. In our case, we are inter- ested in using this method to improve the accuracy of pro- grams which perform floating-point computations, known for their sensitivity to the way formulas are written. We are interested in transforming automatically pieces of code by applying to them several rewriting rules. In this arti- cle, we demonstrate the effectiveness of our approach on a non-trivial numerical simulation code.

Published
2015

31. Impact of Accuracy Optimization on the Convergence of Numerical Iterative Methods

Author

Nasrine Damouche, Matthieu Martel, Alexandre Chapoutot, Ecole Nationale Supérieure de Techniques Avancées - ENSTA (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), LAboratoire de Mathématiques et PhySique (LAMPS), Université de Perpignan Via Domitia (UPVD), Sûreté et Fiabilité des Logiciels (SFL), Unité d'Informatique et d'Ingénierie des Systèmes (U2IS), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris), and ANR-12-INSE-0007,CAFEIN,Combinaison d'approches formelles pour l'étude d'invariants numériques(2012)

Subjects
Mathematical optimization, Numerical Analysis, Floating point, [INFO.INFO-PL]Computer Science [cs]/Programming Languages [cs.PL], Convergence Acceleration, Iterative method, Computer science, Numerical analysis, Floating-Point Numbers, Order of accuracy, Program transformation, IEEE floating point, Program Transformation, Transformation (function), IEEE754 Standard, Autre, Convergence (routing), Convergence acceleration, Algorithm
Abstract

International audience; Among other objectives, rewriting programs serves as a useful technique to improve numerical accuracy. However, this optimization is not intuitive and this is why we switch to automatic transformation techniques. We are interested in the optimization of numerical programs relying on the IEEE754 floating-point arithmetic. In this article, our main contribution is to study the impact of optimizing the numerical accuracy of programs on the time required by numerical iterative methods to converge. To emphasize the usefulness of our tool, we make it optimize several examples of numerical methods such as Jacobi’s method, Newton-Raphson’s method, etc. We show that significant speedups are obtained in terms of number of iterations, time and flops.

Published
2015

32. Intra-procedural Optimization of the Numerical Accuracy of Programs

Author

Matthieu Martel, Alexandre Chapoutot, Nasrine Damouche, Centre National de la Recherche Scientifique - CNRS (FRANCE), Ecole Nationale Supérieure de Techniques Avancées - ENSTA (FRANCE), Université de Montpellier (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier - LIRMM (Montpellier, France), LAboratoire de Mathématiques et PhySique (LAMPS), Université de Perpignan Via Domitia (UPVD), Digits, Architectures et Logiciels Informatiques (DALI), Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier (LIRMM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université de Perpignan Via Domitia (UPVD), Sûreté et Fiabilité des Logiciels (SFL), Unité d'Informatique et d'Ingénierie des Systèmes (U2IS), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris), and ANR-12-INSE-0007,CAFEIN,Combinaison d'approches formelles pour l'étude d'invariants numériques(2012)

Subjects
[INFO.INFO-PL]Computer Science [cs]/Programming Languages [cs.PL], Floating point, Computer science, Floating-Point Numbers, Static Analysis, Program transformation, Static analysis, Abstract interpretation, Set (abstract data type), Program Transformation, IEEE754 Standard, Transformation (function), Autre, Time complexity, Algorithm, Variable (mathematics)
Abstract

International audience; Numerical programs performing floating-point computations are very sensitive to the way formulas are written. These last years, several techniques have been proposed concerning the transformation of arithmetic expressions in order to improve their accuracy and, in this article , we go one step further by automatically transforming larger pieces of code containing assignments and control structures. We define a set of transformation rules allowing the generation, under certain conditions and in polynomial time, of larger expressions by performing limited formal computations, possibly among several iterations of a loop. These larger expressions are better suited to improve the numerical accuracy of the target variable. We use abstract interpretation-based static analysis techniques to over-approximate the roundoff errors in programs and during the transformation of expressions. A prototype has been implemented and experimental results are presented concerning classical numerical algorithm analysis and algorithm for embedded systems.

Published
2015

33. Isolation and characterization of Bradyrhizobium sp. SR1 degrading two β-triketone herbicides

Author

Emilie Rocaboy-Faquet, Sana Romdhane, Marion Devers-Lamrani, Fabrice Martin-Laurent, Jean-François Cooper, Christophe Calvayrac, Lise Barthelmebs, David Riboul, Laboratoire de Chimie des Biomolécules et de l'Environnement (LCBE), Université Montpellier 1 (UM1)-Université de Perpignan Via Domitia (UPVD), Agroécologie [Dijon], Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Laboratoire de Biodiversité et Biotechnologies Microbiennes (LBBM), Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-PIERRE FABRE-EDF (EDF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement - AgroSup Dijon (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Université de Bourgogne - UB (FRANCE), Université Pierre et Marie Curie, Paris 6 - UPMC (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Laboratoire de Chimie des Biomolécules et de l'Environnement ( LCBE ), Université de Perpignan Via Domitia ( UPVD ), Institut National de la Recherche Agronomique ( INRA ) -Université de Bourgogne ( UB ) -AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Laboratoire de Biodiversité et Biotechnologies Microbiennes ( LBBM ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -PIERRE FABRE-EDF ( EDF ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de génie chimique ( LGC ), Institut National Polytechnique [Toulouse] ( INP ) -Université Paul Sabatier - Toulouse 3 ( UPS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Génie Chimique (LGC), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Institut National Polytechnique de Toulouse - INPT (FRANCE), and Université de Perpignan Via Domitia (UPVD)-Université Montpellier 1 (UM1)

Subjects
0301 basic medicine, Biodiversité et Ecologie, Health, Toxicology and Mutagenesis, Metabolite, Leptospermone, 010501 environmental sciences, medicine.disease_cause, 4-Hydroxyphenylpyruvate Dioxygenase, 01 natural sciences, Bradyrhizobium, High resolution mass spectrometry, [ SDV.EE ] Life Sciences [q-bio]/Ecology, environment, Microbiology, Mesotrione, 03 medical and health sciences, chemistry.chemical_compound, Plasmid, β-Triketone, Dioxygenase, Sulcotrione, Escherichia coli, medicine, Environmental Chemistry, Bradyrhizobium sp. SR1, Phylogeny, Soil Microbiology, 0105 earth and related environmental sciences, Ecologie, Environnement, Mesylates, [SDV.EE]Life Sciences [q-bio]/Ecology, environment, [ SDE.BE ] Environmental Sciences/Biodiversity and Ecology, biology, Cyclohexanones, Herbicides, General Medicine, Ribosomal RNA, biology.organism_classification, Pollution, 030104 developmental biology, chemistry, Biodegradation, [SDE.BE]Environmental Sciences/Biodiversity and Ecology
Abstract

International audience; In this study, a bacterial strain able to use sulcotrione,a β-triketone herbicide, as sole source of carbon and energy was isolated from soil samples previously treated with this herbicide. Phylogenetic study based on16S rRNA gene sequence showed that the isolate has 100 % of similarity with several Bradyrhizobium and was accordingly designated as Bradyrhizobium sp. SR1. Plasmid profiling revealed the presence of a large plasmid (>50 kb) in SR1 not cured under nonselective conditions. Its transfer to Escherichia coli by electroporation failed to induce β-triketone degrading capacity,suggesting that degrading genes possibly located on this plasmid cannot be expressed in E. coli or that they are not plasmid borne. The evaluation of the SR1 ability to degrade various synthetic (mesotrione and tembotrione) and natural (leptospermone) triketones showed that this strain was also able to degrademesotrione. Although SR1 was able to entirely dissipate both herbicides, degradation rate of sulcotrione was ten times higher than that of mesotrione, showing a greater affinity of degrading-enzyme system to sulcotrione. Degradation pathway of sulcotrione involved the formation of 2-chloro-4-mesylbenzoic acid (CMBA), previously identified in sulcotrione degradation, and of a new metabolite identified as hydroxy-sulcotrione.Mesotrione degradation pathway leads to the accumulation of-methylsulfonyl-2-nitrobenzoic acid(MNBA) and 2-amino-4 methylsulfonylbenzoic acid(AMBA), two well-known metabolites of this herbicide. Along with the dissipation of β-triketones, one could observe the decrease in 4-hydroxyphenylpyruvate dioxygenase(HPPD) inhibition, indicating that toxicity was due to parent molecules, and not to the formed metabolites. This is the first report of the isolation of bacterial strain able to transform two β-triketones.

Published
2015

34. Statistical exploratory analysis of agent-based simulations in a social context

Author

Villa-Vialaneix, Nathalie, Sibertin-Blanc, Christophe, Roggero, Pascal, Statistique, Analyse et Modélisation Multidisciplinaire (SAmos-Marin Mersenne) (SAMM), Université Paris 1 Panthéon-Sorbonne (UP1), IUT - Département STID - Carcassonne (UPVD), Université de Perpignan Via Domitia (UPVD), Systèmes Multi-Agents Coopératifs (IRIT-SMAC), Institut de recherche en informatique de Toulouse (IRIT), Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire d'Etude et de Recherche sur l'Economie, les Politiques et les Systèmes Sociaux (LEREPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Institut d'Études Politiques [IEP] - Toulouse-École Nationale Supérieure de Formation de l'Enseignement Agricole de Toulouse-Auzeville (ENSFEA), SAMM, Statistique, Analyse, Modélisation Multidisciplinaire, Partenaires INRAE, Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Institut d'Études Politiques [IEP] - Toulouse-École Nationale Supérieure de Formation de l'Enseignement Agricole de Toulouse-Auzeville (ENSFEA), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Centre National de la Recherche Scientifique - CNRS (FRANCE), Ecole Nationale Supérieure de Formation de l'Enseignement Agricole - ENSFEA (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université Paris 1 Panthéon-Sorbonne (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université Toulouse - Jean Jaurès - UT2J (FRANCE), Université Toulouse 1 Capitole - UT1 (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
Organizational behavior, [STAT.AP]Statistics [stat]/Applications [stat.AP], [SHS.SOCIO]Humanities and Social Sciences/Sociology, Self-organizing maps, [SDV]Life Sciences [q-bio], agent-based modeling, self-organizing maps, Système multi-agents, SocLab, organizational behaviour, social simulation, typology, Typology, Social simulation, Agent-based modeling, [INFO.INFO-MA]Computer Science [cs]/Multiagent Systems [cs.MA], Sociologie, F2- Sociologie, Statistiques, H- INFORMATIQUE
Abstract

This paper presents a case study for motivating the use of data mining in a social agent-based simulation framework. The data used in this article come from the social simulation platform SocLab. They were generated from a model designed to analyze a real situation related to the management of a river in the South West of France. Several standard statistical methods are used to analyze the possible outcomes of the discussion between the actors. Finally, a typology of these outcomes is obtained with a self - organizing map. The presentation is accessible to readers with an intermediate level of statistics.

Published
2014

35. Role of substrate outgassing on the formation dynamics of either hydrophilic or hydrophobic wood surfaces in atmospheric-pressure, organosilicon plasmas

Author

Pierre Blanchet, Jérôme Esvan, Eric Bêche, Nicolas Gherardi, Luc Stafford, Andranik Sarkissian, O. Levasseur, Bernard Riedl, Nicolas Naudé, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université de Montréal - UdeM (CANADA), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), FPInnovations (CANADA), Plasmionique (CANADA), Université de Perpignan Via Domitia - UPVD (FRANCE), Université Laval (CANADA), Laboratoire Plasma et Conversion d'Energie - LAPLACE (Toulouse, France), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université de Montréal (UdeM), LAboratoire PLasma et Conversion d'Energie (LAPLACE), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Matériaux et Procédés Plasmas (LAPLACE-MPP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), FPInnovations, and Université Laval [Québec] (ULaval)

Subjects
Hexamethyldisiloxane, Materials science, Matériaux, Biochimie, Organosilicon plasmas, 02 engineering and technology, Ingénierie de l'environnement, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Contact angle, chemistry.chemical_compound, 0103 physical sciences, Materials Chemistry, Organic chemistry, Génie chimique, 010302 applied physics, Functional coatings, Substrate (chemistry), [CHIM.MATE]Chemical Sciences/Material chemistry, Surfaces and Interfaces, General Chemistry, Atmospheric-pressure plasmas, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Black spruce, Dielectric barrier discharges, Wood, Surfaces, Coatings and Films, Outgassing, chemistry, Chemical engineering, Wetting, 0210 nano-technology, Layer (electronics), Deposition (chemistry)
Abstract

International audience; This work examines the influence of substrate outgassing on the deposition dynamics of either hydrophilic or hydrophobic coatings on wood surfaces in organosilicon, dielectric barrier discharges. Sugar maple and black spruce wood samples were placed on the bottom electrode and the discharge was sustained in N2–HMDSO (hexamethyldisiloxane) gas mixtures by applying a 24 kV peak-to-peak voltage at 2 kHz. Current–voltage characteristics revealed a transition from a filamentary to a homogeneous discharge with increasing plasma treatment time, t. Based on opticalemission spectroscopy, the filamentary behaviorwas ascribed to the release of air and humidity from the wood substrate following discharge exposure which produced significant quenching of N2 metastables. This effect vanished at longer treatment times due to the nearly complete “pumping” of products from the wood substrate and the progressive deposition of a “barrier” layer. Analysis of the surface wettability through static, water contact angles (WCAs) and of the surface composition through Fourier-Transform-Infra-Red-Spectroscopy and X-ray-Photoelectron-Spectroscopy indicated that for t b 10 min, the wood surface was more hydrophilic due to the formation of a SiOx layer, a typical behavior for HMDSO deposition in presence of oxygen. On the other hand, for t > 10 min, the static WCA increased up to ~140° due to the deposition of hydrophobic Si(CH3)3-O-Si(CH3)2, Si(CH3)3, and Si(CH3)2 functional groups.

Published
2013

36. Origin and fate of copper in a small Mediterranean vineyard catchment: New insights from combined chemical extraction and δ65Cu isotopic composition

Author

D. El Azzi, Jérôme Viers, Jean-Luc Probst, Dominique Aubert, Anne Probst, Maritxu Guiresse, Katell Guizien, J. Caparros, François Charles, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Pierre et Marie Curie, Paris 6 - UPMC (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Géosciences Environnement Toulouse (GET), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Centre de formation et de recherche sur l'environnement marin (CEFREM), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ecogéochimie des environnements benthiques (LECOB), Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire océanologique de Banyuls (OOB), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Environmental Engineering, chemistry.chemical_element, 010501 environmental sciences, [SDV.SA.SDS]Life Sciences [q-bio]/Agricultural sciences/Soil study, 010502 geochemistry & geophysics, Ecotoxicologie, 01 natural sciences, River sediments, Soil, Non-residual fractions, Isotopes, Environmental Chemistry, Organic matter, Vitis, Waste Management and Disposal, 0105 earth and related environmental sciences, chemistry.chemical_classification, geography, geography.geographical_feature_category, Bedrock, Science des sols, Agriculture, 15. Life on land, Particulates, Pollution, Copper, 6. Clean water, Leaching model, Fungicides, Industrial, chemistry, Environmental chemistry, Soil water, Storm runoff, Soils, France, [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology, Cu isotopes, Surface runoff, Surface water, Suspended matter, Geology
Abstract

International audience; For centuries, many Mediterranean catchments were covered with vineyards in which copper was widely applied to protect grapevines against fungus. In the Mediterranean-type flow regime, brief and intense flood events increase the stream water discharge by up to 10 times and cause soil leaching and storm runoff. Because vineyards are primarily cultivated on steep slopes, high Cu fluxes are discharged by surface water runoff into the rivers. The purpose of this work was to investigate the riverine behavior and transport of anthropogenic Cu by coupling a sequential chemical extraction (SCE) procedure, used to determine Cu partitioning between residual and non-residual fractions, with δ65Cu isotopic measurements in each fraction. In the Baillaury catchment, France, we sampled soils (cultivated and abandoned), river bed sediments (BS), suspended particulate matter (SPM), and river water during the flash flood event of February 2009. Copper partitioning using SCE show that most of Cu in abandoned vineyard soil was in the residual phase (>60%) whereas in cultivated soil, BS and SPM, Cu was mostly (>25%) in non-residual fractions, mainly adsorbed onto iron oxide fractions. A small fraction of Cu was associated with organic matter (5 to 10%). Calculated enrichment factors (EF) are higher than 2 and the anthropogenic contribution was estimated between 50 to 85%. Values for δ65Cu in bulk samples were similar to bedrock therefore; δ65Cu on SCE fractions of superficial soils and SPM allowed for discrimination between Cu origin and distribution. Copper in residual fractions was of natural mineral origin (δ65Cu close to local bedrock, +0.07‰). Copper in water soluble fraction of SPM (δ65Cu = +0.26‰) was similar to dissolved river Cu (δ65Cu = +0.31‰). Copper from fungicide treatment (δ65Cu = −0.35‰) was bound to organic matter (δ65Cu = −0.20‰) without or with slight isotopic fractioning. A preferential adsorption of 65Cu onto iron oxides (δ65Cu = +0.5‰) is shown.

Published
2013

37. Recent climatic and anthropogenic imprints on lacustrine systems in the Pyrenean Mountains inferred from minerogenic and organic clastic supply (Vicdessos valley, Pyrenees, France)

Author

Anaëlle Simonneau, Edouard Bard, Marc Desmet, Mikael Motellica-Heino, Florence Mazier, Thierry Courp, Thomas Houet, Emmanuel Chapron, Gaël Le Roux, Sandrine Baron, Christian Di Giovanni, Anthony Foucher, Kazuyo Tachikawa, Didier Galop, Marta Garcia, Aix-Marseille Université - AMU (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Collège de France (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université Toulouse - Jean Jaurès - UT2J (FRANCE), Bureau de Recherches Géologiques et Minières - BRGM (FRANCE), Ministère de la culture et de la communication (FRANCE), Université d'Orléans (FRANCE), Université de Tours (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Géographie de l'environnement (GEODE), Université Toulouse - Jean Jaurès (UT2J)-Centre National de la Recherche Scientifique (CNRS), Centre de formation et de recherche sur l'environnement marin (CEFREM), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Chaire Evolution du climat et de l'océan, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Travaux et recherches archéologiques sur les cultures, les espaces et les sociétés (TRACES), École des hautes études en sciences sociales (EHESS)-Université Toulouse - Jean Jaurès (UT2J)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), GéoHydrosystèmes COntinentaux (GéHCO EA6293), Université de Tours, Labex DRIIHM - CNRS INEE, Artemis radiocarbon committee (INSU/CNRS), ANR-11-LABX-0010,DRIIHM / IRDHEI,Dispositif de recherche interdisciplinaire sur les Interactions Hommes-Milieux(2011), PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse - Jean Jaurès (UT2J), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), ANR-11-LABX-0010/11-LABX-0010,LabEx DRIIHM,Dispositif de recherche interdisciplinaire sur les Interactions Hommes-Milieux(2011), Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Collège de France - Chaire Evolution du climat et de l'océan, Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), École des hautes études en sciences sociales (EHESS)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Université de Tours (UT), Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), and Ministère de la Culture et de la Communication (MCC)-École des hautes études en sciences sociales (EHESS)-Université Toulouse - Jean Jaurès (UT2J)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010506 paleontology, Archeology, Watershed, 010504 meteorology & atmospheric sciences, [SDE.MCG]Environmental Sciences/Global Changes, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, mid-late Holocene, Structural basin, 01 natural sciences, Trophic state, Glacial period, Holocene, 0105 earth and related environmental sciences, Earth-Surface Processes, Hydrology, Canyon, Ecologie, Environnement, Global and Planetary Change, geography, geography.geographical_feature_category, soil erosion, Ecology, Pyrenees, Paleontology, Sediment, 15. Life on land, [SDE.ES]Environmental Sciences/Environmental and Society, hydropower, lake sediment, Lake sediment, 13. Climate action, Clastic rock, Soil erosion, Sedimentary rock, Physical geography, Environnement et Société, Geology, Hydropower, Mid–late Holocene
Abstract

International audience; High-resolution seismic profiling has been combined with geochemical analyses of both watershed samples and five lacustrine cores retrieved from two natural lacustrine basins of glacial origin: Lake Majeur and Lake Sigriou (1630 m a.s.l. and 1995 m a.s.l., respectively, Eastern French Pyrenees). Identifying specific minerogenic and organic markers of autochthonous and allochthonous supply, data allow documenting past climatic and anthropogenic pressures. Over the past century, the lacustrine sediment of Lake Majeur has been essentially composed of algae, drastically contrasting with the natural sedimentary infill of the basin, mainly resulting from soil erosion from the mid-late Holocene. Since ad 1907, the Lake Majeur has been used for hydroelectricity production. Human-induced lake-level regulations, affecting up to 37% of the lacustrine surface, have increased by fourfold the accumulation rate of the lake and favoured water enrichment. Rubidium abundance within the lacustrine sediments of the two lakes reflects the mid-late Holocene palaeohydrology. After dam construction in ad 1907, greater quantities of rubidium found in Lake Majeur sedimentary infills indicate drier climatic periods, such as from ad 1975 to ad 1982, during which water reservoirs were particularly in demand. Inversely, before the dam was built, rubidium fluctuations were correlated with wetter conditions and hydrological events were recorded as sandy layers deposited by canyon reactivation, synchronous with European climatic deterioration phases. We notably document that the Mediaeval Climate Anomaly was interrupted by some humid periods dated c. ad 940, ad 1080, ad 1100 and ad 1250. We also date the onset of the 'Little Ice Age' c. ad 1360 and identify that this period was wetter after c. ad 1500.

Published
2013

38. New insights on Cu origin and fate from combined chemical extraction and ᵟ⁶⁵Cu isotopic composition: Application to Cu transfers in a Mediterranean vineyard catchment

Author

El Azzi, Désirée, Viers, Jérôme, Guiresse, Agnès Maritchù, Probst, Anne, Aubert, Dominique, Caparros, Jocelyne, Charles, François, Guizien, Katell, Probst, Jean-Luc, Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Géosciences Environnement Toulouse (GET), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ecogéochimie des environnements benthiques (LECOB), Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National d'Études Spatiales - CNES (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Pierre et Marie Curie, Paris 6 - UPMC (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
Non-residual fractions, Isotopes, Science des sols, Flood event, Mediterranean, [SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology, [SDV.SA.SDS]Life Sciences [q-bio]/Agricultural sciences/Soil study, Hydrologie, Vineyard catchment, Copper, Residual fraction
Abstract

International audience; Repeated use of Cu based fungicides (Bordeaux mixture: Ca(OH)2+CuSO4) to control vine downy hasled to signi!cant increase of Cu in vineyard soils. In Mediterranean catchments, brief and intense flood events can multiply stream discharge by up to 10 and are responsible for important soil leaching and therefore for high "uxes of Cu exported at the outlet of the catchment. In order to assess the origin and fate of Cu measured in the Baillaury catchment (South of France, combined sequential extraction (SCE) and isotopic Cu compositions (δ65Cu) approaches are proposed in this study.

Published
2012

39. Impact of oceanic floods on particulate metal inputs to coastal and deep-sea environments: A case study in the NW Mediterranean Sea

Author

Jean-Luc Probst, Cécile Guieu, Olivier Radakovitch, N. Delsaut, André Monaco, Vincent Roussiez, Wolfgang Ludwig, Xavier Durrieu de Madron, Serge Heussner, Centre de formation et de recherche sur l'environnement marin (CEFREM), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Laboratoire d'océanographie de Villefranche (LOV), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Observatoire océanologique de Villefranche-sur-mer (OOVM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Aix-Marseille Université - AMU (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Collège de France (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Pierre et Marie Curie, Paris 6 - UPMC (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
Mediterranean climate, Fluvial system, 010504 meteorology & atmospheric sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 010501 environmental sciences, Aquatic Science, Oceanography, 01 natural sciences, Deep sea, Sciences de la Terre, Océanographie, Mediterranean sea, 14. Life underwater, Lion continental-shelf, Organic-carbon, Biogeochemical implications, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Flood myth, Continental shelf, Temporal variability, Geology, Storm, Trace-metals, Advective transport, Particulates, 13. Climate action, Heavy-metals, Suspended sediment, Sediment transport, Rhone river France
Abstract

International audience; An exceptional flood event, accompanying a marine storm, was investigated simultaneously at the entrance and the exit of the Gulf of Lion's hydrosystem (NW Mediterranean) in December 2003. Cs, Cr, Co, Ni, Cu, Zn, Cd and Pb signatures of both riverine and shelf-exported particles indicate that continental inputs and resuspended prodeltaic sediments were intensively mixed with resuspended sediments from middle/outer shelf areas during advective transport. As a result, particles leaving the Gulf of Lion inherited the mean signature of shelf bottom sediments, exporting anthropogenic Pb and Zn out into the open sea. When assessing the particulate metal budget in relation with the event, it appears that the output fluxes accounted for between 15% and 60% of the input fluxes, depending on the element and the period of reference. This trend is also observed for annual budgets, which were drawn up by compiling the data from this study and the literature. Results evidenced that, except some element fluxes during extreme output scenario, outputs never counter-balance the inputs. In its current functioning, the Gulf of Lion's shelf seems to act as a retention/sink zone for particulate metals. Regarding anthropogenic fluxes, the contribution of the oceanic flood of December 2003 to the mean annual scenario is considerable. Environmental impacts onto coastal and deep-sea ecosystems should therefore tightly depend on both the intensity and the frequency of event-dominated sediment transport.

Published
2012

40. Fate of metals in coastal sediments of a Mediterranean flood-dominated system: An approach based on total and labile fractions

Author

Olivier Radakovitch, Vincent Roussiez, André Monaco, Bruno Charrière, Roselyne Buscail, Jean-Luc Probst, Wolfgang Ludwig, Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique - CNRS (FRANCE), Collège de France (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Provence - Aix-Marseille I (FRANCE), Université de la Méditerranée - Aix-Marseille II (FRANCE), Université Paul Cézanne - Aix-Marseille III (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), and Institut National Polytechnique de Toulouse - INPT (FRANCE)

Subjects
Mediterranean climate, SURFICIAL SEDIMENTS, 010504 meteorology & atmospheric sciences, Biodiversité et Ecologie, NW SPAIN, metals, 010501 environmental sciences, Aquatic Science, Oceanography, SCHELDT ESTUARY, CHEMICAL-COMPOSITION, 01 natural sciences, sediment dynamics, PARTICULATE HEAVY-METALS, Océan, Atmosphère, riverborne sediments, CONTINENTAL-SHELF, Mediterranean sea, contamination, TRACE-METALS, Contamination, Labile fraction, Organic matter, 14. Life underwater, Early diagenetic processes, Gulf of Lion, 0105 earth and related environmental sciences, chemistry.chemical_classification, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, geography, geography.geographical_feature_category, Continental shelf, labile fraction, Sediment, early diagenetic processes, Sediment dynamics, Particulates, SEQUENTIAL EXTRACTION PROCEDURE, PARTICLE-SIZE, Diagenesis, ORGANIC-MATTER, chemistry, 13. Climate action, Metals, Environmental chemistry, Sedimentary rock, Riverborne sediments, Geology
Abstract

The dynamics of sediment-bound metals (Cs, Cu, Ni, Pb, Ti and Zn) were studied off the Tet River (western Gulf of Lion), a typical Mediterranean coastal river punctuated by short and violent flash-floods. Spatial and temporal sampling strategies were combined to elucidate the fate of these elements in response to both the riverine sediment input and the offshore transport of these sediments through hydrodynamics. Our results show the temporal entrapment of riverborne particles and associated metals, consecutively to a major flood event, in the nearshore sedimentary unit called prodelta. Here, deposition and resuspension mechanisms define a sedimentological cycle that could be followed completely in this study. In terms of speciation between reactive (labile) and residual fractions along the fluvio-deltaic continuum, our results show that Cu, Pb and Zn are the most labile (potentially mobile) metals in the river, in accordance with their contributions from anthropogenic sources. But in the marine surficial sediments, two main behaviours can be discriminated when compared to the riverine suspended particulate matter. While Pb and Zn depict rather a constant labile fraction, Cu is characterized by decreasing levels (up to 50% difference). In terms of environmental impact, these contrasting trends have direct repercussions for the contaminant dispersal in the coastal area. Whereas Pb and Zn conserve their enhanced levels because of their stronger affinity with fine sediments, Cu is marked by the entire loss of its anthropogenic component that is progressively transferred to the dissolved phase, likely mediated by organic ligands. We ascribe these behaviours to different post-depositional partition mechanisms with respect to oxidation of the particulate organic phase at the bottom sediment/water interface. Also, analysis of one sediment core from the prodelta indicates that these early diagenetic processes govern the chemical forms of land-derived contaminants sequestrated in the nearshore sedimentary archives. (C) 2011 Elsevier Ltd. All rights reserved.

Published
2011

41. Comment on 'The biosphere: A homogeniser of Pb-isotope signals' by C. Reimann, B. Flem, A. Arnoldussen, P. Englmaier, T.E. Finne, F. Koller and Ø. Nordgulen

Author

Gaël Le Roux, Christophe Cloquet, François De Vleeschouwer, Dominique Aubert, Jeroen E. Sonke, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Liège (BELGIUM), Silesian University of Technology (POLAND), Université de Lorraine (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Laboratoire des Mécanismes et Transferts en Géologie - LMTG (Toulouse, France), Laboratoire des Mécanismes et Transfert en Géologie (LMTG), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Centre de géochimie de la surface (CGS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Unité de Recherche Argiles et Paléoclimats, Université de Liège, Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Silesian University of Technology, Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Louis Pasteur - Strasbourg I-Institut national des sciences de l'Univers (INSU - CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Peat, 010504 meteorology & atmospheric sciences, [SDE.MCG]Environmental Sciences/Global Changes, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 010501 environmental sciences, Atmospheric sciences, 01 natural sciences, Atmosphere, Isotopic signature, Biosphere, Geochemistry and Petrology, Coal burning, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Environmental Chemistry, Table (landform), Transect, [SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Isotope, Comment, Géochimie, Pollution, Géologie appliquée, Lead, 13. Climate action, Homogeniser, Physical geography, Geology
Abstract

International audience; Reimann et al. (2008) recently published a study on Pb-isotope signature along a 120 km long transect cutting the city of Oslo. Based on concentration but also isotope data, they misinterpret Pb concentration of the biosphere in rural places and explain these large enrichments of Pb as being due to natural processes. The study ignores numerous previous studies either on local, regional or global scales (see reviews by Shotyk and Le Roux, 2005 and Callender, 2003, and references therein), which clearly demonstrate that anthropogenic Pb emitted in the atmosphere from different sources (leaded gasoline, coal burning, metallurgy, etc.) was and is dispersed worldwide. The study also ignores work on Norway by the Steinnes and colleagues group (Harmens et al., 2008, Steinnes et al., 2005a, Steinnes et al., 2005b and Åberg et al., 2004), and measurements and modelling by the EMEP network (www.emep.int/, EMEP, 2005). The study also neglects numerous works on preanthropogenic Pb deposition rate and isotopic signature using continental archives of atmospheric deposition like peat bogs (Shotyk et al., 1998, Klaminder et al., 2003, Kylander et al., 2005 and Le Roux et al., 2005). These studies have shown that preanthropogenic Pb atmospheric deposition rate and its Pb isotopic signature is regionally defined, but also that those signals are negligible compared to past 2 ka and recent Pb atmospheric fluxes (Table 1).

Published
2008

42. Predicting the impact of land use on the major element and nutrient fluxes in coastal Mediterranean rivers: The case of the Teˆt River (Southern France)

Author

Wolfgang Ludwig, Philippe Kerhervé, Jean-Luc Probst, Franck Lespinas, Javier Garcia-Esteves, Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Mécanismes et Transfert en Géologie (LMTG), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
Mediterranean climate, South of France, 010504 meteorology & atmospheric sciences, Weathering, Context (language use), 010501 environmental sciences, Structural basin, 01 natural sciences, Geographical Information System (GIS), Nutrient, Typical small coastal, Geochemistry and Petrology, Agricultural land, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Environmental Chemistry, Effluent, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Hydrology, Land use, Géochimie, Anthropogenic sources, 15. Life on land, Vineyards, Pollution, 6. Clean water, 13. Climate action, Environmental science
Abstract

International audience; This study presents a detailed discrimination between the natural and anthropogenic sources of dissolved major elements in the Teˆt River, a typical small coastal river in the south of France. The main objectives were to quantify the materials that were released by human activities in the basin, and to determine the specific element inputs for the major land use forms. The dissolved material fluxes were estimated by weekly monitoring over a hydrological year (2000–2001) along the major water gauging stations, and the flux relationships were examined in the context of anthropogenic and natural basin characteristics as determined by a Geographical Information System (GIS). Intensive agricultural land use in the form of fruit tree cultures and vineyards has a strong control on the dissolved element fluxes in the river. Area specific element releases for these cultures are greatest for SO4, with an estimated average of about 430 ± 18 keq km2 a1. This is P11 times the natural SO4 release by rock weathering. Also for K, NO3, PO4 and Mg, the specific releases were P6 times the natural weathering rates (respectively about 44, 60, 4 and 265 keq km2 a1). Waste-waters are the other major source of anthropogenic elements in the river. They have an important role for the fluxes of inorganic P and N, but they are also a considerable source of Cl and Na to the river. For example, the average annual release of Cl is around 150 moles/inhabitant in the rural basin parts. Further downstream, however, where population density strongly increases, industrial effluents can enhance this value (>300 moles/inhabitant). The waste-waters contribute more than 70% of the dissolved inorganic N export to the sea, although their contribution to the average DOC export is almost negligible (3%).

Published
2007

43. Sources and sinks of sediment-bound contaminants in the Gulf of Lions (NW Mediterranean Sea): a multi-tracer approach

Author

Ioanna Bouloubassi, André Monaco, Jean-Luc Probst, Gilles Saragoni, Wolfgang Ludwig, Roselyne Buscail, Vincent Roussiez, Centre de formation et de recherche sur l'environnement marin (CEFREM), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Mécanismes et Transfert en Géologie (LMTG), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Pierre et Marie Curie, Paris 6 - UPMC (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)

Subjects
010504 meteorology & atmospheric sciences, [SDE.MCG]Environmental Sciences/Global Changes, 010501 environmental sciences, Aquatic Science, Silt, Oceanography, 01 natural sciences, chemistry.chemical_compound, Mediterranean sea, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Contaminants, 14. Life underwater, Repository areas, Riverborne and aerosol sources, 0105 earth and related environmental sciences, Total organic carbon, geography, Coprostanol, geography.geographical_feature_category, Continental shelf, Géochimie, Sediment, Geology, Sedimentation, Contamination, 6. Clean water, Heavy metals, chemistry, 13. Climate action, Environmental chemistry, Gulf of Lions
Abstract

Surficial sediments collected in 2002 throughout the Gulf of Lions continental shelf (NW Mediterranean) were analysed for trace metals (Cd, Co, Cr, Cs, Cu, Ni, Pb, Sr, Zn and Zr), major elements (Al, Ca, Fe, P and Ti) and the sewage marker coprostanol. In addition, particle size distribution, organic carbon (OC) and carbonates were also determined. Results showed that the metal contamination (Cd, P, Cu, Pb and Zn) is mainly introduced by the local rivers and accumulates—via a regulation by OC and silt fraction (2–63 μm)—in the direct vicinity of the mouths, in high shear stress environments. Here also the signal of sewage contamination is the best preserved, especially off the eastern point sources where local sedimentation rates save the faecal marker from biodegradation processes. It is demonstrated that the shallow prodeltas are the first repository areas for land-derived particles, exposing local ecosystems to both inorganic and organic contaminations. When going seaward, however, sediment dilution, particle sorting and biodegradation processes make that most riverborne contaminants rapidly reach natural levels. Only some metals (i.e. Pb and Zn)—closely associated with the clay fraction—still depict anthropogenic enrichment, which seems to be inherited from man-made aerosols.

Published
2006

44. The impact of vegetation on fractionation of rare earth elements(REE) during water–rock interaction

Author

Dominique Aubert, Anne Probst, François Gauthier-Lafaye, Peter Stille, Marie-Claire Pierret, Daniel Viville, Marc Steinmann, François Chabaux, Centre National d'Études Spatiales - CNES (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Louis Pasteur-Strasbourg I - ULP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Franche-Comté (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Centre de géochimie de la surface (CGS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université Louis Pasteur - Strasbourg I-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
Water–rock interaction, media_common.quotation_subject, Speciation, Rare earth, Geochemistry, Drainage basin, Weathering, Fractionation, 010501 environmental sciences, 010502 geochemistry & geophysics, 01 natural sciences, Apatite, Geochemistry and Petrology, Dissolution, Rare earth elements, 0105 earth and related environmental sciences, media_common, geography, geography.geographical_feature_category, Vegetation, Géochimie, 15. Life on land, River water, 13. Climate action, visual_art, visual_art.visual_art_medium, Economic Geology, Geology
Abstract

Previous studies on waters of a streamlet in the Vosges mountains (eastern France) have shown that Sr and rare earth elements (REE) principally originate from apatite dissolution during weathering. However, stream water REE patterns normalized to apatite are still depleted in light REE (LREE, La–Sm) pointing to the presence of an additional LREE depleting process. Speciation calculations indicate that complexation cannot explain this additional LREE depletion. In contrast, vegetation samples are strongly enriched in LREE compared to water and their Sr and Nd isotopic compositions are comparable with those of apatite and waters. Thus, the preferential LREE uptake by the plants at the root–water–soil (apatite) interface might lead to an additional LREE depletion of the waters in the forested catchment. Mass balance calculations indicate that the yearly LREE uptake by vegetation is comparable with the LREE export by the streamlet and, therefore, might be an important factor controlling the LREE depletion in river waters.

Published
2006

45. Background levels of heavy metals in surficial sediments of the Gulf of Lions (NW Mediterranean): An approach based on 133Cs normalization and lead isotope measurements

Author

Vincent Roussiez, André Monaco, Jean-Luc Probst, Wolfgang Ludwig, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Mécanismes et Transfert en Géologie (LMTG), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
Pollution, Normalization (statistics), Mediterranean climate, Geologic Sediments, Health, Toxicology and Mutagenesis, media_common.quotation_subject, Mineralogy, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Cesium, Background levels, Toxicology, Sciences de la Terre, Mediterranean sea, Isotopes, Metals, Heavy, Coastal sediments, Mediterranean Sea, Soil Pollutants, Soil Pollutants, Radioactive, Particle Size, Cs, media_common, Isotope analysis, Isotope, General Medicine, Lead isotopes, Normalization, Lead, Heavy metals, Gulf of Lions, France, Enrichment factor, Clay minerals, Geology, Environmental Monitoring
Abstract

International audience; This paper presents an attempt to reach natural background levels of heavy metals in surficial sediments of the Gulf of Lions(NW Mediterranean). To correct for the grain-size effect, normalization procedures based on a clay mineral indicator element are commonly used, after a first grain size separation by sieving. In our study, we tested the applicability of this method with respect to commonly used normalizer elements, and found that stable Cs shows the best ability to reflect the fine sediment fraction. Background levels were successfully reached for Co, Cr, Cu, Ni and Pb, compared to various literature references. Nevertheless, in the case of lead, the normalized data depicted a general enrichment in all samples, and the natural levels could only be reached when concentrations were corrected for the atmospheric contribution by analysing lead isotope ratios. Also for Zn, a general enrichment was found in our samples, although less important.

Published
2005

46. Sediment fluxes of the Sebou river (Morocco)

Author

Souad Haida, Maria Snoussi, Jean-Luc Probst, Université Ibn Tofaïl (UIT), Université Mohammed V de Rabat [Agdal] (UM5), Laboratoire des Mécanismes et Transfert en Géologie (LMTG), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Mohammed V de Rabat, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Pierre et Marie Curie, Paris 6 - UPMC (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université Ibn Tofail (MOROCCO), Université Mohammed V-Rabat - UM5 (MOROCCO), Université de La Rochelle (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Laboratoire des Mécanismes et Transferts en Géologie - LMTG (Toulouse, France), and Institut National Polytechnique de Toulouse - INPT (FRANCE)

Subjects
Trap efficiency, [SDE.IE]Environmental Sciences/Environmental Engineering, Impact of dams, Ingénierie de l'environnement, Sebou river, Water discharge, Siltation, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Ecosystèmes, [SHS.ENVIR]Humanities and Social Sciences/Environmental studies, Life-span, Semiarid region, Sediment fluxes, Etudes de l'environnement
Abstract

International audience; Annual pre-dam and post-dam data for one of Morocco’s largest rivers, the Sebou,were analysed using there water discharge and suspended sediment loads. Results from theses analyses indicated significant reduction of water discharge and sediment fluxes by 70 and 95% respectively. Otherwise, the Sebou reservoirs,suffered from siltation due to the high rate of natural and accelerated erosion. In fact, the trap efficiency calculated for the Sebou dams ranges from 85-99%, and their life-span from 42-910 years. For instance, Al Wahda, the second largest dam of Africa, with a capacity of 3.8 103 Km3, takes 374 years to be filled with sediments. This huge siltation has a serious environmental and socio-economical impact, since it reduces the reservoirs capacity, and could affect the morphological equilibrium of the coastline. In semiarid region, environmental impacts of dams are particularly emphasised because of the irregular nature of climate and the intensity of erosive forces.

Published
2004

47. Digital modelling and stereolithographic production of a Homo Erectus skull

Author

Emmanuel Cabanis, Marie-Antoinette de Lumley, Farid Taha, François Pérès, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université de Technologie de Compiègne – UTC (FRANCE), Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts - CHNO (FRANCE), Museum National d'Histoire Naturelle - MNHN (FRANCE), Université de Perpignan Via Domitia - UPVD (FRANCE), Histoire Naturelle de l’Homme Préhistorique - HNHP (Paris, France), Laboratoire Génie de Production (LGP), Ecole Nationale d'Ingénieurs de Tarbes, Université de Technologie de Compiègne (UTC), Histoire naturelle de l'Homme préhistorique (HNHP), Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Université de Perpignan Via Domitia (UPVD), Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Université de Perpignan Via Domitia (UPVD), Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts (CHNO), and Muséum national d'Histoire naturelle (MNHN)-Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0209 industrial biotechnology, biology, Anthropology, Evolution, Mechanical Engineering, 02 engineering and technology, 010502 geochemistry & geophysics, biology.organism_classification, 01 natural sciences, Industrial and Manufacturing Engineering, Modelling, Skull, 020901 industrial engineering & automation, Geography, medicine.anatomical_structure, Rapid prototypes, medicine, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, Traitement du signal et de l'image, Head (anatomy), Homo erectus, Scientific study, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, 0105 earth and related environmental sciences, Imagerie médicale
Abstract

International audience; The National Museum of Natural History has been carrying out, over the last several years, a study of hominid fossil skulls, which have been discovered in different regions of the world. The aim of the palaeo‐anthropological study of these skulls is to reconstruct the genealogic tree of the evolution of man and to understand better, the diversity of the homo Erectus species on the different continents. Currently, digital techniques and those of rapid prototyping offer a solution to these problems by allowing the virtual or physical reconstitution of the skulls for scientific study. This paper presents this new perspective for the world of palaeontology.

Published
2004

48. Worldwide distribution of continental rock lithology: Implications for the atmospheric/soil CO2 uptake by continental weathering and alkalinity river transport to the oceans

Author

Amiotte Suchet, Philippe, Probst, Jean-Luc, Ludwig, Wolfgang, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université de Bourgogne - UB (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
Global carbon cycle, River basins, Riverine inputs to oceans, Géochimie, Modeling, Spatial distribution, Lithological map
Abstract

The silicate rock weathering followed by the formation of carbonate rocks in the ocean, transfers CO2 from the atmosphere to the lithosphere. This CO2 uptake plays a major role in the regulation of atmospheric CO2 concentrations at the geologic timescale and is mainly controlled by the chemical properties of rocks. This leads us to develop the first world lithological map with a grid resolution of 1 1. This paper analyzes the spatial distribution of the six main rock types by latitude, continents, and ocean drainage basins and for 49 large river basins. Coupling our digital map with the GEM-CO2 model, we have also calculated the amount of atmospheric/soil CO2 consumed by rock weathering and alkalinity river transport to the ocean. Among all silicate rocks, shales and basalts appear to have a significant influence on the amount of CO2 uptake by chemical weathering

Published
2003

49. Enhanced chemical weathering of rocks during the last glacial maximum: a sink for atmospheric CO2?

Author

Philippe Amiotte-Suchet, Wolfgang Ludwig, Jean-Luc Probst, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Université de Bourgogne - UB (FRANCE), Université Louis Pasteur-Strasbourg I - ULP (FRANCE), and Université de Perpignan Via Domitia - UPVD (FRANCE)

Subjects
geography, geography.geographical_feature_category, Chemical weathering, Continental shelf, Earth science, Climate oscillation, Géochimie, Last glacial maximum, Geology, Last Glacial Maximum, Weathering, Géologie appliquée, Geochemistry and Petrology, Climatology, Interglacial, Atmospheric CO2, Glacial period, Ice sheet, Sea level
Abstract

It has been proposed that increased rates of chemical weathering and the related drawdown of atmospheric CO2 on the continents may have at least partly contributed to the low CO2 concentrations during the last glacial maximum (LGM). Variations in continental erosion could thus be one of the driving forces for the glacial/interglacial climate cycles during Quaternary times. To test such an hypothesis, a global carbon erosion model has been applied to a LGM scenario in order to determine the amount of CO2 consumed by chemical rock weathering during that time. In this model, both the part of atmospheric CO2 coming from silicate weathering and the part coming from carbonate weathering are distinguished. The climatic conditions during LGM were reconstructed on the basis of the output files from a computer simulation with a general circulation model. Only the predicted changes in precipitation and temperature have been used, whereas the changes in continental runoff were determined with an empirical method. It is found that during the LGM, the overall atmospheric CO2 consumption may have been greater than today (by about 20%), mainly because of greater carbonate outcrop area related to the lower sea level on the shelves. This does not, however, affect the atmospheric CO2 consumption by silicate weathering, which alone has the potential to alter atmospheric CO2 on the long-term. Silicate weathering and the concomitant atmospheric CO2 consumption decreased together with a global decrease of continental runoff compared to present-day (both by about 10%). Nevertheless, some uncertainty remains because the individual lithologies of the continental shelves as well as their behavior with respect to chemical weathering are probably not well enough known. The values we present refer to the ice-free continental area only, but we tested also whether chemical weathering under the huge ice sheets could have been important for the global budget. Although glacial runoff was considerably increased during LGM, weathering under the ice sheets seems to be of minor importance.

Published
1999

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