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1. Recessed and P-GaN regrowth gate development for normally-off AlGaN/GaN HEMTs

Author: Yvon Cordier, Gaatan Toulon, Mathieu Gavelle, Chaymaa Haloui, Josiane Tasselli, Karine Isoird, Eric Frayssinet, Frédéric Morancho, Équipe Intégration de Systèmes de Gestion de l'Énergie (LAAS-ISGE), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Exagan, Centre de recherche sur l'hétéroepitaxie et ses applications (CRHEA), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), CEA Tech Occitanie (DOCC), CEA Tech en régions (CEA-TECH-Reg), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), HALOUI, Chaymaa, Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Université Nice Sophia Antipolis (... - 2019) (UNS), and CEA Tech Languedoc-Roussillon Midi-Pyrénées
Subjects: 010302 applied physics, Materials science, 010308 nuclear & particles physics, business.industry, [SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Wide-bandgap semiconductor, Algan gan, Normally off, Heterojunction, High-electron-mobility transistor, Integrated circuit, 01 natural sciences, law.invention, Threshold voltage, law, 0103 physical sciences, Optoelectronics, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, business, Layer (electronics)
Abstract: International audience; A new normally-off AlGaN/GaN HEMT structure is proposed. The regrowth of a P-GaN layer on the AlGaN/GaN heterostructure after the gate recess allows the achievement of the enhancement mode. A shift in the threshold voltage to positive values has been proved through simulation results. A precise control of the etch depth for the gate recess is detailed.
Published: 2020

2. Numerical Simulation for DC Schottky Gate Leakage Current in AlGaN/GaN HEMTs

Author: Antonio Nunez, Gaëtan Toulon, Benito Gonzalez, Javier Garcia, Frédéric Morancho, and R. Rodriguez
Subjects: 010302 applied physics, Materials science, Computer simulation, Subthreshold conduction, business.industry, Wide-bandgap semiconductor, Algan gan, Schottky gate, Gallium nitride, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, chemistry.chemical_compound, chemistry, Logic gate, 0103 physical sciences, Optoelectronics, 0210 nano-technology, business, Leakage (electronics)
Abstract: Different causes of the gate leakage origin in AlGaN/GaN HEMTs on Si have been studied through numerical simulations. Based on DC measured results and employing Sentaurus Device, different trap effects under the Schottky gate must be included to reproduce the measured transfer characteristics in subthreshold regime. Additionally, numerical simulation aspects for GaN-based HEMTs are also detailed.
Published: 2018
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3. A new electro-optical transmission-line measurement-method revealing a possible contribution of source and drain contact resistances to GaN HEMT dynamic on-resistance

Author: David Trémouilles, Dany Hachem, Gaëtan Toulon, Frédéric Morancho, Équipe Intégration de Systèmes de Gestion de l'Énergie (LAAS-ISGE), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), LABEX GaNeX, Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: Materials science, Source and drain contact resistances, Gallium nitride, 02 engineering and technology, High-electron-mobility transistor, 01 natural sciences, law.invention, chemistry.chemical_compound, Dynamic on-resistance, Reliability (semiconductor), law, Power electronics, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Power semiconductor device, Electrical and Electronic Engineering, Safety, Risk, Reliability and Quality, UV illumination, HEMT, 010302 applied physics, Transmission line measurement, business.industry, 020208 electrical & electronic engineering, Transistor, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, [SPI.TRON]Engineering Sciences [physics]/Electronics, Gallium Nitride, Semiconductor, chemistry, Trapping phenomena, Optoelectronics, business
Abstract: International audience; Despite their potential in the field of power electronics, many reliability issues still affect the electrical performance of Gallium Nitride HEMT power devices and require an effort of analysis and understanding. The characterization of the on-state resistance of this transistor is necessary to understand the dynamics of some phenomena such as trapping. The degradation of this resistance has always been related to traps in the 2DEG channel, without taking into consideration possible contributions from the source and drain contacts (metal/ semiconductor). In this work, resistance measurements, with and without ultraviolet illumination, are performed on three different technological options to highlight the effect of illumination on contact resistances.
Published: 2018
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4. Analysis and optimisation of lateral thin-film silicon-on-insulator (SOI) PMOS transistor with an NBL layer in the drift region

Author: Gaëtan Toulon, Bruno Villard, David Flores, I. Cortes, Frédéric Morancho, Elsa Hugonnard-Bruyère, Centro Nacional de Microelectronica [Spain] (CNM), Équipe Intégration de Systèmes de Gestion de l'Énergie (LAAS-ISGE), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), ATMEL [Rousset], MEDEA +, SPOT-2 (ATMEL / LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: Engineering, Silicon on insulator, Hardware_PERFORMANCEANDRELIABILITY, 02 engineering and technology, NBL, 01 natural sciences, PMOS logic, law.invention, law, 0103 physical sciences, Hardware_INTEGRATEDCIRCUITS, Materials Chemistry, Electronic engineering, Electrical and Electronic Engineering, Thin film, 010302 applied physics, TCAD, business.industry, CMOS, Transistor, RESURF, P-channel, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Variable bitrate, LDMOS, [SPI.TRON]Engineering Sciences [physics]/Electronics, Electronic, Optical and Magnetic Materials, Power (physics), Optoelectronics, 0210 nano-technology, business, Layer (electronics), Thin-SOI technology, Voltage
Abstract: International audience; This paper analyses the experimental results of voltage capability (VBR > 120 V) and output characteristics of a new lateral power P-channel MOS transistors manufactured on a 0.18 μm SOI CMOS technology by means of TCAD numerical simulations. The proposed LDPMOS structures have an N-type buried layer (NBL) inserted in the P-well drift region with the purpose of increasing the RESURF effectiveness and improving the static characteristics (Ron-sp/VBR trade-off) and the device switching performance. Some architecture modifications are also proposed in this paper to further improve the performance of fabricated transistors.
Published: 2012
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5. Design of a fiber-collimated array for beam combining

Author: Jérôme Primot, Thomas Bouvet, Bruno Toulon, Lionel Quetel, Arnaud Brignon, Stephan Megtert, Cindy Bellanger, Faycal Bouamrane, Tristan Allain, ONERA - The French Aerospace Lab [Palaiseau], ONERA-Université Paris Saclay (COmUE), Thales Research and Technology [Palaiseau], THALES, ONERA - The French Aerospace Lab [Châtillon], Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), Centre National de la Recherche Scientifique (CNRS)-THALES, IDIL Fibres Optiques, and PME
Subjects: Materials science, Optical engineering, 02 engineering and technology, 01 natural sciences, Collimated light, [SPI.AUTO]Engineering Sciences [physics]/Automatic, 010309 optics, 020210 optoelectronics & photonics, Optics, Fiber laser, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Fiber, Microlens, COLLIMATED FIBER ARRAY, business.industry, BEAM COMBINING, General Engineering, Atomic and Molecular Physics, and Optics, FIBER LASERS, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, Laser beam quality, business, Phase modulation, Beam (structure)
Abstract: International audience; In this paper, we present the design of a very precise collimated fiber array that meets requirements for beam combining. Calculations permit to determine the tolerances toward key parameters and specify the components to manufacture. Thus, the collimated fiber array is composed of a high quality commercial microlens array and an especially dedicated fiber holder that we design and realize experimentally. Manufacture techniques for both the microlens and the holder are chosen to be collective and then compatible with a high number of fibers. With the collimated fiber array hence obtained, the individual beam quality was measured to be λ/10 and the pointing accuracy is under 0.6 mrad.
Published: 2015
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6. Step-selective measurement by grating-based lateral shearing interferometry for segmented telescopes

Author: Riad Haïdar, Sabrina Velghe, Bruno Toulon, Jérôme Primot, Raymond Mercier, Nicolas Guérineau, ONERA - The French Aerospace Lab [Châtillon], ONERA-Université Paris Saclay (COmUE), Laboratoire Charles Fabry de l'Institut d'Optique / Scop, Laboratoire Charles Fabry de l'Institut d'Optique (LCFIO), and Université Paris-Sud - Paris 11 (UP11)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 02 engineering and technology, Grating, 01 natural sciences, law.invention, 010309 optics, Optics, law, 0103 physical sciences, Astronomical interferometer, Chromatic scale, Electrical and Electronic Engineering, Physical and Theoretical Chemistry, ComputingMilieux_MISCELLANEOUS, Physics, Wavefront, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, 021001 nanoscience & nanotechnology, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Interferometry, Shearography, Achromatic lens, 0210 nano-technology, Shearing interferometer, business
Abstract: We present an original step-selective mode which allows to measure only the steps and not the slowly varying aberrations of a wave front. This mode can be implemented when measuring segmented wave front by a diffraction-grating-based lateral shearing interferometer. This set-up rests on the different chromatic response of these interferometers depending on the rate of change of the impinging wave front: for smooth defects, the response is classically achromatic whereas it is chromatic for a step variation, which was to our knowledge overlooked. The interest of this mode for astronomical measurements is highlighted. First we present theoretical considerations to show how this mode of measure is possible; then a numerical simulation illustrates them.
Published: 2007

7. Role of apoplast acidification by the H+ pump

Author: Hervé Sentenac, Jean-Claude Davidian, Claire Moulineau, Claude Grignon, Jean-Baptiste Thibaud, Valérie Toulon, Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
Subjects: 0106 biological sciences, Titration curve, [SDV]Life Sciences [q-bio], Bicarbonate, Plant Science, 01 natural sciences, chemistry.chemical_compound, Proton transport, Genetics, medicine, Chelation, Vanadate, Iron deficiency (plant disorder), COLZA, ComputingMilieux_MISCELLANEOUS, 04 agricultural and veterinary sciences, Apoplast, REDUCTION, chemistry, Biochemistry, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Ferric, 010606 plant biology & botany, Nuclear chemistry, medicine.drug
Abstract: We have studied the mechanism of the response to iron deficiency in rape (Brassica napus L.), taking into account our previous results: net H(+) extrusion maintains a pH shift between the root apoplast and the solution, and the magnitude of the pH shift decreases as the buffering power in the solution increases. The ferric stress increased the ability of roots to reduce Fe[III]EDTA. Buffering the bulk solution (without change in pH) inhibited Fe[III]EDTA reduction. At constant bulk pH, the inhibition (ratio of the Fe[III]EDTA-reduction rates measured in the presence and in the absence of buffer) increased with the rate of H(+) extrusion (modulated by the length of a pretreatment in 0.2 mM CaSO4). These results support the hypothesis that the apoplastic pH shift caused by H(+) excretion stimulated Fe[III] reduction. The shape of the curves describing the pH-dependency of Fe[III]EDTA reduction in the presence and in the absence of a buffer fitted this hypothesis. When compared to the titration curves of Fe[III]citrate and of Fe[III]EDTA, the curves describing the dependency of the reduction rate of these chelates on pH indicated that the stimulation of Fe[III] reduction by the apoplastic pH shift due to H(+) excretion could result from changes in electrostatic interactions between the chelates and the fixed chargers of the cell wall and-or plasmalemma. Blocking H(+) excretion by vanadate resulted in complete inhibiton of Fe[III] reduction, even in an acidic medium in which there was neither a pH shift nor an inhibitory effect of a buffer. This indicates that the apoplastic pH shift resulting from H(+) pumping is not the only mechanism which is involved in the coupling of Fe[III] reduction to H(+) transport. Our results shed light on the way by which the strong buffering effect of HCO 3 (-) in some soils may be involved in iron deficiency encountered by some of the plants which grow in them.
Published: 1992
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8. Effect of HCO - (3) concentration in the absorption solution on the energetic coupling of H(+)-cotransports in roots of Zea mays L

Author: Jean-Baptiste Thibaud, André Soler, David T. Clarkson, Hervé Sentenac, Claude Grignon, and Valérie Toulon
Subjects: 0106 biological sciences, Absorption (pharmacology), chemistry.chemical_classification, Diffusion, Inorganic chemistry, 04 agricultural and veterinary sciences, Plant Science, Sulfonic acid, 01 natural sciences, Acetic acid, chemistry.chemical_compound, chemistry, Proton transport, Carbon dioxide, 040103 agronomy & agriculture, Genetics, 0401 agriculture, forestry, and fisheries, Cotransporter, Ion transporter, 010606 plant biology & botany
Abstract: The effect of HCO 3 (-) on ion absorption by young corn roots was studied in conditions allowing the independent control of both the pH of uptake solution and the CO2 partial pressure in air bubbled through the solution. The surface pH shift in the vicinity of the outer surface of the plasmalemma induced by active H(+) excretion was estimated using the initial uptake rate of acetic acid as a pH probe (Sentenac and Grignon (1987) Plant Physiol. 84, 1367). Acetic acid and orthophosphate uptake rates and NO 3 (-) accumulation were slowed down, while (86)Rb(+) uptake and K(+) accumulation rates were increased by HCO 3 (-) . These effects were similar to those induced by 4-(2-hydroxyethyl)-1-piperazineethane sulfonic acid/2-amino-2-(hydroxymethyl)-1,3-propanediol (Hepes-Tris). They were more pronounced when the H(+) excretion was strong, were rapidly reversible and were not additive to those of Hepes-Tris. The hypothesis is advanced that the buffering system CO2/H2CO3/HCO 3 (-) accelerated the diffusion of equivalent H(+) inside the cell wall towards the medium. This attenuated the surface pH shift in the vicinity the plasma membrane and affected the coupling between the proton pump and cotransport systems.
Published: 1989

9. Nucleation in sessile saline microdroplets: induction time measurement via deliquescence–recrystallization cycling

Author: Ruel Cedeno, Romain Grossier, Mehdi Lagaize, David Nerini, Nadine Candoni, Adrian Flood, Stéphane Veesler, Vidyasirimedhi Institute of Science and Technology, Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), 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)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU), Vidyasirimedhi Institute of Science and Technology [Thaïlande] (VISTEC), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), 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), and Eiffel Excellence Scholarship (N°P744524E)
Subjects: optical microscopy, Condensed Matter - Materials Science, 010405 organic chemistry, nucleation, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, contraction, 010402 general chemistry, sessile droplets, 01 natural sciences, evaporation, image processing, [SPI.MAT]Engineering Sciences [physics]/Materials, 0104 chemical sciences, induction time, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Physical and Theoretical Chemistry
Abstract: International audience; Induction time, a measure of how long one will wait for nucleation to occur, is an important parameter in quantifying nucleation kinetics and its underlying mechanisms. Due to the stochastic nature of nucleation, efficient methods for measuring large number of independent induction times are needed to ensure statistical reproducibility. In this work, we present a novel approach for measuring and analyzing induction times in sessile arrays of microdroplets via deliquescence/recrystallization cycling. With the help of a recently developed image analysis protocol, we show that the interfering diffusion-mediated interactions between microdroplets can be eliminated by controlling the relative humidity, thereby ensuring independent nucleation events. Moreover, possible influence of heterogeneities, impurities, and memory effect appear negligible as suggested by our 2-cycle experiment. Further statistical analysis (k-sample Anderson-Darling test) reveals that upon identifying possible outliers, the dimensionless induction times obtained from different datasets (microdroplet lines) obey the same distribution and thus can be pooled together to form a much larger dataset. The pooled dataset showed an excellent fit with the Weibull function, giving a mean supersaturation at nucleation of 1.61 and 1.85 for the 60pL and 4pL microdroplet respectively. This confirms the effect of confinement where smaller systems require higher supersaturations to nucleate. Both the experimental method and the data-treatment procedure presented herein offer promising routes in the study of fundamental aspects of nucleation kinetics, particularly confinement effects, and are adaptable to other salts, pharmaceuticals, or biological crystals of interest.
Published: 2022
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10. Magnetic and New Optical Properties in the UV–visible Range of the Egyptian Blue Pigment Cuprorivaite CaCuSi4O10

Author: Laurent Binet, Sylvain Bertaina, Juliette Lizion, Didier Gourier, Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), ANR-17-CE29-0002,ESCULAPE,Le spin électronique: un nouvel outil pour l'héritage culturel et la protection de la population(2017), and Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)
Subjects: Luminescence, Materials science, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics, 02 engineering and technology, Photochemistry, 01 natural sciences, Egyptian blue, chemistry.chemical_compound, Pigment, 0103 physical sciences, Physical and Theoretical Chemistry, 010306 general physics, Astrophysics::Galaxy Astrophysics, Condensed Matter::Quantum Gases, Egyptian Blue, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Electron Paramagnetic Resonance, General Energy, chemistry, Cuprorivaite, visual_art, Visible range, visual_art.visual_art_medium, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el], 0210 nano-technology
Abstract: International audience; Cuprorivaite CaCuSi4O10, the so-called Egyptian blue pigment, exhibits a characteristic and well-known near-infrared luminescence upon excitation in Cu2+d–d transitions. Here, we show that upon excitation in the UV, this near-infrared emission is considerably amplified and is accompanied by three different UV–visible emission bands. These four UV-excited emissions are attributed to self-trapped excitons (emission at 2.8 eV), to excitons trapped at Cu sites (emission at 1.4 eV), and to trapped exciton emission where the hole is only trapped at Cu sites (emissions at 2.65 and 3.27 eV). Despite the high Cu content of cuprorivaite, electron magnetic resonance reveals only a weak antiferromagnetic interaction (about 0.08 meV), which averages out the hyperfine interaction of the electron spin with nuclear spins of 63Cu and 65Cu nuclei.
Published: 2021
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11. Influential groups for seeding and sustaining nonlinear contagion in heterogeneous hypergraphs

Author: Guillaume St-Onge, Iacopo Iacopini, Vito Latora, Alain Barrat, Giovanni Petri, Antoine Allard, Laurent Hébert-Dufresne, Université Laval [Québec] (ULaval), Centre de Physique Théorique - UMR 7332 (CPT), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), CPT - E5 Physique statistique et systèmes complexes, Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Queen Mary University of London (QMUL), ISI Foundation Institute for Scientific Interchange, and ANR-19-CE46-0008,DataRedux,Réduction de données massives pour la simulation numérique prédictive(2019)
Subjects: Physics - Physics and Society, Physics, QC1-999, Complex networks, FOS: Physical sciences, General Physics and Astronomy, Physics and Society (physics.soc-ph), Computer Science::Social and Information Networks, Nonlinear phenomena, Astrophysics, 01 natural sciences, 010305 fluids & plasmas, QB460-466, Phase transitions and critical phenomena, 0103 physical sciences, [PHYS.COND.CM-SM]Physics [physics]/Condensed Matter [cond-mat]/Statistical Mechanics [cond-mat.stat-mech], 010306 general physics
Abstract: Several biological and social contagion phenomena, such as superspreading events or social reinforcement, are the results of multi-body interactions, for which hypergraphs offer a natural mathematical description. In this paper, we develop a novel mathematical framework based on approximate master equations to study contagions on random hypergraphs with a heterogeneous structure, both in terms of group size (hyperedge cardinality) and of membership of nodes to groups (hyperdegree). The characterization of the inner dynamics of groups provides an accurate description of the contagion process, without losing the analytical tractability. Using a contagion model where multi-body interactions are mapped onto a nonlinear infection rate, our two main results show how large groups are influential, in the sense that they drive both the early spread of a contagion and its endemic state (i.e., its stationary state). First, we provide a detailed characterization of the phase transition, which can be continuous or discontinuous with a bistable regime, and derive analytical expressions for the critical and tricritical points. We find that large values of the third moment of the membership distribution suppress the emergence of a discontinuous phase transition. Furthermore, the combination of heterogeneous group sizes and nonlinear contagion facilitates the onset of a mesoscopic localization phase, where contagion is sustained only by the largest groups, thereby inhibiting bistability as well. Second, we formulate the problem of optimal seeding for hypergraph contagion, and we compare two strategies: tuning the allocation of seeds according to either individual node or group properties. We find that, when the contagion is sufficiently nonlinear, groups are more effective seeds of contagion than individual nodes., 23 pages, 12 figures (main text); 6 pages, 3 figures (supplementary information)
Published: 2022
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12. La0.8Pb0.1Ca0.1Fe1−xCoxO3 thin films as ozone-sensitive layers

Author: M. Bejar, Marc Bendahan, Khalifa Aguir, S. Smiy, E. Dhahri, Tomas Fiorido, Université de Sfax - University of Sfax, Laboratoire de sciences des matériaux et de l’environnement [Université de Sfax] (SME), Faculté des Sciences de Sfax, Université de Sfax - University of Sfax-Université de Sfax - University of Sfax, Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), and Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)
Subjects: Materials science, Ozone concentration, Thin films, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, [SPI]Engineering Sciences [physics], Ozone, Drop coating, Perovskites, Sensitivity (control systems), Electrical and Electronic Engineering, Thin film, ComputingMilieux_MISCELLANEOUS, Co-doped, Volume concentration, Sensors, [SDE.IE]Environmental Sciences/Environmental Engineering, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Crystallography, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, Realization (systems)
Abstract: This paper describes the realization and characterization of $${\text{La}}_{0.8}{\text{Pb}}_{0.1}{\text{Ca}}_{0.1}{\text{Fe}}_{1-x}{\text{Co}}_{x}{\text{O}}_{3}$$ gas-based sensors. $${\text{La}}_{0.8}{\text{Pb}}_{0.1}{\text{Ca}}_{0.1}{\text{Fe}}_{1-x}{\text{Co}}_{x}{\text{O}}_{3}$$ $$(0.00\le x\le 0.20)$$ thin films are prepared using the drop-coating method over a $${\text{Si}}/{\text{SiO}}_{2}$$ substrate with inter-digitated $${\text{Pt}}$$ -electrodes. The sensors, thus, produced exhibit a good sensitivity to ozone at low concentration. The substitution of iron atoms by cobalt ones increases the sensor responses “S,” from 1.716 for $$x = 0.00$$ to 6.584 to $$x = 0.20$$ for an ozone concentration equal to $$400\,{\text{ppb}}$$ . In addition, the substitution of iron by cobalt induces a decrease in the sensor-operating temperature from $$270\,^\circ{\text{C}}$$ for the parent compound $$(x = 0.00)$$ to $$170\,^\circ{\text{C}}$$ for $$x = 0.20$$ .
Published: 2021
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13. Stable recovery of noncompactly supported electromagnetic potentials in unbounded domain

Author: Yavar Kian, Yosra Soussi, Centre de Physique Théorique - UMR 7332 (CPT), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), CPT - E8 Dynamique quantique et analyse spectrale, Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Université de Tunis El Manar (UTM), and ANR-17-CE40-0029,MultiOnde,Problèmes Inverses Multi-Onde(2017)
Subjects: General Mathematics, 010102 general mathematics, Mathematical analysis, General Engineering, 01 natural sciences, Domain (software engineering), 010101 applied mathematics, Mathematics - Analysis of PDEs, 35R30, FOS: Mathematics, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], Electromagnetic potential, 0101 mathematics, ComputingMilieux_MISCELLANEOUS, Analysis of PDEs (math.AP), Mathematics
Abstract: We consider the inverse problem of determining an electromagnetic potential appearing in an infinite cylindrical domain from boundary measurements. More precisely, we prove the stable recovery of some general class of magnetic field and electric potential from boundary measurements. Assuming some knowledge of the unknown coefficients close to the boundary, we obtain also some results of stable recovery with measurements restricted to some portion of the boundary. Our approach combines construction of complex geometric optics solutions and Carleman estimates suitably designed for our stability results stated in an unbounded domain.
Published: 2021
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14. A semi-alternating algorithm for solving nonconvex split equality problems

Author: Abdellatif Moudafi, Laboratoire des Sciences de l'Information et des Systèmes (LSIS), Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Paristech ENSAM Aix-en-Provence-Université de Toulon (UTLN)-Aix Marseille Université (AMU), MOUDAFI, Abdellatif, and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Arts et Métiers Paristech ENSAM Aix-en-Provence-Centre National de la Recherche Scientifique (CNRS)
Subjects: Mathematical optimization, Control and Optimization, Iterative method, 010102 general mathematics, [MATH] Mathematics [math], 16. Peace & justice, 01 natural sciences, Computer Science Applications, 010101 applied mathematics, Statistics::Machine Learning, Signal Processing, [MATH]Mathematics [math], 0101 mathematics, Analysis, Mathematics
Abstract: In this paper, we propose an iterative method for solving split equality problems in the nonconvex setting. Relying on the associated penalized optimization formulation, we study a relevant iterati...
Published: 2021
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15. Quadratic transportation inequalities for SDEs with measurable drift

Author: Soufiane Mouchtabih, Ludovic Tangpi, Khaled Bahlali, Institut de Mathématiques de Toulon - EA 2134 (IMATH), and Université de Toulon (UTLN)
Subjects: Computer Science::Machine Learning, General Mathematics, Sobolev regularity, MathematicsofComputing_GENERAL, Computer Science::Digital Libraries, 01 natural sciences, Statistics::Machine Learning, 010104 statistics & probability, symbols.namesake, Stochastic differential equation, Quadratic equation, Wiener process, FOS: Mathematics, 0101 mathematics, Mathematics, Applied Mathematics, Probability (math.PR), 010102 general mathematics, Mathematical analysis, Sigma, Quadratic transportation inequality, [MATH.MATH-PR]Mathematics [math]/Probability [math.PR], Sobolev space, singular drifts, Stochastic differential equations, Computer Science::Mathematical Software, symbols, Computer Science::Programming Languages, Mathematics - Probability, Differential (mathematics)
Abstract: Let X X be the solution of a stochastic differential equation in Euclidean space driven by standard Brownian motion, with measurable drift and Sobolev diffusion coefficient. In our main result we show that when the drift is measurable and the diffusion coefficient belongs to an appropriate Sobolev space, the law of X X satisfies Talagrand’s inequality with respect to the uniform distance.
Published: 2021
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16. Lower-Bounds on the Growth of Power-Free Languages Over Large Alphabets

Author: Matthieu Rosenfeld, Laboratoire d'Informatique et Systèmes (LIS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Algorithmique, Combinatoire et Recherche Opérationnelle (ACRO), and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: FOS: Computer and information sciences, Discrete Mathematics (cs.DM), media_common.quotation_subject, 010103 numerical & computational mathematics, 0102 computer and information sciences, [INFO.INFO-DM]Computer Science [cs]/Discrete Mathematics [cs.DM], 01 natural sciences, Upper and lower bounds, Theoretical Computer Science, Combinatorics, Integer, FOS: Mathematics, Mathematics - Combinatorics, Beta (velocity), Growth rate, 0101 mathematics, ComputingMilieux_MISCELLANEOUS, media_common, Physics, Conjecture, Infinity, Computational Theory and Mathematics, 010201 computation theory & mathematics, Combinatorics (math.CO), Alphabet, Computer Science - Discrete Mathematics
Abstract: We study the growth rate of some power-free languages. For any integer k and real β > 1, we let α(k,β) be the growth rate of the number of β-free words of a given length over the alphabet {1,2,…,k}. Shur studied the asymptotic behavior of α(k,β) for β ≥ 2 as k goes to infinity. He suggested a conjecture regarding the asymptotic behavior of α(k,β) as k goes to infinity when 1 < β
Published: 2021
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17. Genomic evidence for global ocean plankton biogeography shaped by large-scale current systems

Author: Richter, Daniel J., Watteaux, Romain, Vannier, Thomas, Leconte, Jade, Frémont, Paul, Reygondeau, Gabriel, Maillet, Nicolas, Henry, Nicolas, Benoit, Gaëtan, da Silva, Ophélie, Delmont, Tom O., Fernández-Guerra, Antonio, Suweis, Samir, Narci, Romain, Berney, Cedric, Eveillard, Damien, Gavory, Frederick, Guidi, Lionel, Labadie, Karine, Mahieu, Eric, Poulain, Julie, Romac, Sarah, Roux, Simon, Dimier, Céline, Kandels‐Lewis, Stefanie, Picheral, Marc, Searson, Sarah, Oceans, Tara, Pesant, Stéphane, Aury, Jean-Marc, Brum, Jennifer R., Lemaitre, Claire, Pelletier, Eric, Bork, Peer, Sunagawa, Shinichi, Lombard, Fabien, Karp-Boss, Lee, Bowler, Chris, Sullivan, Matthew B., Karsenti, Eric, Mariadassou, Mahendra, Probert, Ian, Peterlongo, Pierre, Wincker, Patrick, Vargas, Colomban de, Ribera d’Alcalà, Maurizio, Iudicone, Daniele, Jaillon, Olivier, Tara Oceans Coordinators, Centre National de la Recherche Scientifique (France), European Molecular Biology Laboratory, Centre National de Séquençage (France), National Fund for Scientific Research (Belgium), Stazione Zoologica Anton Dohrn, Università degli Studi di Milano, Université Paris Sciences & Lettres, Agence Nationale de la Recherche (France), National Science Foundation (US), Veolia Foundation, Région Bretagne, World Courier, Illumina, Cap L’Orient, Fondation EDF, Fondation pour la Recherche sur la Biodiversité, Fondation Prince Albert II de Monaco, Ministère de l'Europe et des Affaires étrangères (France), Adaptation et diversité en milieu marin (ADMM), Institut national des sciences de l'Univers (INSU - CNRS)-Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Stazione Zoologica Anton Dohrn (SZN), 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)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Institut de Génomique d'Evry (IG), Université Paris-Saclay-Institut de Biologie François JACOB (JACOB), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Genoscope - Centre national de séquençage [Evry] (GENOSCOPE), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), University of British Columbia (UBC), Hub Bioinformatique et Biostatistique - Bioinformatics and Biostatistics HUB, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Max Planck Institute for Marine Microbiology, Max-Planck-Gesellschaft, Dipartimento di Fisica e Astronomia 'Galileo Galilei', Università degli Studi di Padova = University of Padua (Unipd), Consorzio Nazionale Interuniversitario per le Scienze FIsiche della Materia (CNISM), Mathématiques et Informatique Appliquées du Génome à l'Environnement [Jouy-En-Josas] (MaIAGE), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Numérique de Nantes (LS2N), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Combinatoire et Bioinformatique (LS2N - équipe COMBI), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Institut de Biologie François JACOB (JACOB), Ohio State University [Columbus] (OSU), Institut de biologie de l'ENS Paris (IBENS), Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-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)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Ecology and Evolutionary Biology [Tucson] (EEB), University of Arizona, Scalable, Optimized and Parallel Algorithms for Genomics (GenScale), Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-GESTION DES DONNÉES ET DE LA CONNAISSANCE (IRISA-D7), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Rennes 1 (UR1), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), European Molecular Biology Laboratory [Heidelberg] (EMBL), University of Maine, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Fédération de recherche de Roscoff (FR2424), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), French National Research Agency (ANR)HYDROGEN/ANR-14CE23-0001, National Science Foundation (NSF)OCE-1536989, OCE-1829831, Commissariat a l'Energie Atomique et aux Energies Alternatives, Graphene Flagship, European Project: 634486,H2020,H2020-BG-2014-2,INMARE(2015), European Project: 287589,EC:FP7:KBBE,FP7-OCEAN-2011,MICRO B3(2012), Adaptation et diversité en milieu marin (AD2M), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Universita degli Studi di Padova, Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Combinatoire et Bioinformatique (COMBI), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff (SBR), Centre de Mathématiques et de Leurs Applications (CMLA), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN)-Aix Marseille Université (AMU)-Institut de Recherche pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS)-Institut Pasteur [Paris], Infectiologie Santé Publique (ISP-311), Institut National de la Recherche Agronomique (INRA)-Université de Tours, Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA), Laboratoire d'Informatique de Nantes Atlantique (LINA), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS), Institut de biologie de l'ENS Paris (UMR 8197/1024) (IBENS), École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université de Bretagne Sud (UBS)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National de Recherche en Informatique et en Automatique (Inria)-École normale supérieure - Rennes (ENS Rennes)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-CentraleSupélec-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Bretagne Sud (UBS)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-École normale supérieure - Rennes (ENS Rennes)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1)
Subjects: 010504 meteorology & atmospheric sciences, Biogeography, Oceans and Seas, Context (language use), 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, 03 medical and health sciences, plankton biogeography, genomics, Ecosystem, genetics, 14. Life underwater, microbial oceanography, 030304 developmental biology, 0105 earth and related environmental sciences, Seascape, [SDV.EE]Life Sciences [q-bio]/Ecology, environment, 0303 health sciences, metagenomics, General Immunology and Microbiology, Geography, General Neuroscience, Ocean current, fungi, Community structure, General Medicine, 15. Life on land, Plankton, Oceanography, 13. Climate action, Metagenomics, metabarcoding, ecology, [INFO.INFO-BI]Computer Science [cs]/Bioinformatics [q-bio.QM]
Abstract: Biogeographical studies have traditionally focused on readily visible organisms, but recent technological advances are enabling analyses of the large-scale distribution of microscopic organisms, whose biogeographical patterns have long been debated. Here we assessed the global structure of plankton geography and its relation to the biological, chemical, and physical context of the ocean (the ‘seascape’) by analyzing metagenomes of plankton communities sampled across oceans during the Tara Oceans expedition, in light of environmental data and ocean current transport. Using a consistent approach across organismal sizes that provides unprecedented resolution to measure changes in genomic composition between communities, we report a pan-ocean, size-dependent plankton biogeography overlying regional heterogeneity. We found robust evidence for a basin-scale impact of transport by ocean currents on plankton biogeography, and on a characteristic timescale of community dynamics going beyond simple seasonality or life history transitions of plankton., We thank the commitment of the following people and sponsors who made this expedition possible: CNRS (in particular Groupement de Recherche GDR3280), European Molecular Biology Laboratory (EMBL), Genoscope/CEA, Fund for Scientific Research – Flanders, VIB, Stazione Zoologica Anton Dohrn, UNIMIB, Paris Sciences et Lettres (PSL) Research University (ANR-11-IDEX-0001–02), the French Government ANR (projects FRANCE GENOMIQUE/ANR-10-INBS-09, MEMO LIFE/ANR-10-LABX-54, POSEIDON/ANR-09-BLAN-0348, PROMETHEUS/ANR-09-PCS-GENM-217, MAPPI/ANR-2010-COSI-004, TARA-GIRUS/ANR-09-PCS-GENM-218), US NSF grant DEB-1031049, FWO, BIO5, Biosphere 2, Agnès b., the Veolia Environment Foundation, Région Bretagne, World Courier, Illumina, Cap L’Orient, the EDF Foundation EDF Diversiterre, FRB, the Prince Albert II de Monaco Foundation, Etienne Bourgois, the Tara schooner and its captain and crew. We thank MERCATOR-CORIOLIS and ACRI-ST for providing daily satellite data during the expedition. The bulk of genomic computations were performed using the Airain HPC machine provided through GENCI- [TGCC/CINES/IDRIS] (grants t2011076389, t2012076389, t2013036389, t2014036389, t2015036389 and t2016036389). We are also grateful to the French Ministry of Foreign Affairs for supporting the expedition and to the countries who granted us sampling permissions.
Published: 2022
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18. Symmetry-Forbidden-Mode Detection in SrTiO3 Nanoislands with Tip-Enhanced Raman Spectroscopy

Author: Jiawei Zhang, François Légaré, Alborz Ehteshami, Alexandre Merlen, Gitanjali Kolhatkar, Andreas Ruediger, Chahinez Dab, Azza Hadj Youssef, Dorothée Berthomieu, Énergie Matériaux Télécommunications - INRS (EMT-INRS), Institut National de la Recherche Scientifique [Québec] (INRS)-Université du Québec à Montréal = University of Québec in Montréal (UQAM), Kiel University, Université de Montréal (UdeM), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Tip-enhanced Raman spectroscopy, 01 natural sciences, Molecular physics, Symmetry (physics), 3. Good health, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, symbols.namesake, General Energy, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], symbols, Physical and Theoretical Chemistry, 0210 nano-technology, Raman spectroscopy, ComputingMilieux_MISCELLANEOUS
Abstract: Among the techniques to reveal the chemistry, structure, and dynamics of surfaces, tip-enhanced Raman spectroscopy (TERS) occupies a unique position for the investigation of nonmetallic nanomateria...
Published: 2021
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19. Eternal Domination: D-Dimensional Cartesian and Strong Grids and Everything in Between

Author: Stéphane Pérennes, Fionn Mc Inerney, Nicolas Nisse, Combinatorics, Optimization and Algorithms for Telecommunications (COATI), Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-COMmunications, Réseaux, systèmes Embarqués et Distribués (Laboratoire I3S - COMRED), Laboratoire d'Informatique, Signaux, et Systèmes de Sophia Antipolis (I3S), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Laboratoire d'Informatique, Signaux, et Systèmes de Sophia Antipolis (I3S), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), Aix Marseille Université (AMU), Inria & Université Cote d'Azur, CNRS, I3S, Sophia Antipolis, France, Aix-Marseille Université, Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Laboratoire d'Informatique, Signaux, et Systèmes de Sophia Antipolis (I3S), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), Algorithmique, Combinatoire et Recherche Opérationnelle (ACRO), Laboratoire d'Informatique et Systèmes (LIS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), ANR-17-CE40-0015,DISTANCIA,Théorie métrique des graphes(2017), COMmunications, Réseaux, systèmes Embarqués et Distribués (Laboratoire I3S - COMRED), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Inria Sophia Antipolis - Méditerranée (CRISAM), and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)
Subjects: General Computer Science, Domination analysis, Strong grid, King's graph, 0102 computer and information sciences, 02 engineering and technology, [INFO.INFO-DM]Computer Science [cs]/Discrete Mathematics [cs.DM], Computer Science::Computational Geometry, 01 natural sciences, Omega, law.invention, Combinatorics, Computer Science::Discrete Mathematics, law, 0202 electrical engineering, electronic engineering, information engineering, [INFO]Computer Science [cs], Cartesian coordinate system, Physics, Mathematics::Combinatorics, Applied Mathematics, Grids, 16. Peace & justice, Graph, Computer Science Applications, Vertex (geometry), Cartesian grid, 010201 computation theory & mathematics, Combinatorial Games, 020201 artificial intelligence & image processing, Eternal Domination, Graphs
Abstract: In the eternal domination game played on graphs, an attacker attacks a vertex at each turn and a team of guards must move a guard to the attacked vertex to defend it. The guards may only move to adjacent vertices on their turn. The goal is to determine the eternal domination number $$\gamma ^{\infty }_{all}$$ of a graph, which is the minimum number of guards required to defend against an infinite sequence of attacks. This paper first continues the study of the eternal domination game on strong grids $$P_n\boxtimes P_m$$ . Cartesian grids $$P_n \square P_m$$ have been vastly studied with tight bounds existing for small grids such as $$k\times n$$ grids for $$k\in \{2,3,4,5\}$$ . It was recently proven that $$\gamma ^{\infty }_{all}(P_n \square P_m)=\gamma (P_n \square P_m)+O(n+m)$$ where $$\gamma (P_n \square P_m)$$ is the domination number of $$P_n \square P_m$$ which lower bounds the eternal domination number [Lamprou et al. Eternally dominating large grids. Theoretical Computer Science, 794:27–46, 2019]. We prove that, for all $$n,m\in \mathbb {N^*}$$ such that $$m\ge n$$ , $$\lfloor \frac{n}{3} \rfloor \lfloor \frac{m}{3} \rfloor +\Omega (n+m)=\gamma _{all}^{\infty } (P_{n}\boxtimes P_{m})=\lceil \frac{n}{3} \rceil \lceil \frac{m}{3} \rceil + O(m\sqrt{n})$$ (note that $$\lceil \frac{n}{3} \rceil \lceil \frac{m}{3} \rceil$$ is the domination number of $$P_n\boxtimes P_m$$ ). We then generalise our technique to prove that $$\gamma _{all}^{\infty }(G)=\gamma (G)+o(\gamma (G))$$ for all graphs $$G\in {\mathcal {F}}$$ , where $${\mathcal {F}}$$ is a large family of D-dimensional grids which are supergraphs of the D-dimensional Cartesian grid and subgraphs of the D-dimensional strong grid. In particular, $${\mathcal {F}}$$ includes both the D-dimensional Cartesian grid and the D-dimensional strong grid.
Published: 2021
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20. Well-Posedness for Weak and Strong Solutions of Non-Homogeneous Initial Boundary Value Problems for Fractional Diffusion Equations

Author: Masahiro Yamamoto, Yavar Kian, Centre de Physique Théorique - UMR 7332 (CPT), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), CPT - E8 Dynamique quantique et analyse spectrale, Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), and ANR-17-CE40-0029,MultiOnde,Problèmes Inverses Multi-Onde(2017)
Subjects: Spacetime, Applied Mathematics, 010102 general mathematics, Mathematical analysis, Boundary (topology), 35R11, 35B30, 35R05, 01 natural sciences, 010101 applied mathematics, Sobolev space, Strong solutions, Mathematics - Analysis of PDEs, Compatibility (mechanics), FOS: Mathematics, Fractional diffusion, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], Boundary value problem, 0101 mathematics, Analysis, Well posedness, Analysis of PDEs (math.AP), Mathematics
Abstract: International audience; Abstract We study the well-posedness for initial boundary value problems associated with time fractional diffusion equations with non-homogenous boundary and initial values. We consider both weak and strong solutions for the problems. For weak solutions, we introduce a definition of solutions which allows to prove the existence of solution to the initial boundary value problems with non-zero initial and boundary values and non-homogeneous source terms lying in some negative-order Sobolev spaces. For strong solutions, we introduce an optimal compatibility condition and prove the existence of the solutions. We introduce also some sharp conditions guaranteeing the existence of solutions with more regularity in time and space.
Published: 2021
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21. Total phosphorus determination in eutrophic tropical river sediments by laser-induced breakdown spectroscopy techniques

Author: Frederico Fábio Mauad, Gustavo Nicolodelli, Stéphane Mounier, Carla Pereira de Morais, Milene Corso Mitsuyuki, Débora Marcondes Bastos Pereira Milori, Kleydson Stênio Gaioso da Silva, Embrapa Instrumentation (CNPDIA), National Nanotechnology Laboratory for Agriculture (LNNA), 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), Instituto de Química de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-Carlense 400, São Carlos, SP, Brazil, Departamento Física [Florianópolis], Universidade Federal de Santa Catarina = Federal University of Santa Catarina [Florianópolis] (UFSC), Sao Carlos School of engineering [São Paulo], University of São Paulo (USP), 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), and Universidade de São Paulo = University of São Paulo (USP)
Subjects: Detection limit, FÓSFORO, Calibration curve, General Chemical Engineering, 010401 analytical chemistry, General Engineering, Sediment, 010501 environmental sciences, 01 natural sciences, 6. Clean water, 0104 chemical sciences, Analytical Chemistry, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, 13. Climate action, Environmental chemistry, Inductively coupled plasma atomic emission spectroscopy, Environmental science, Laser-induced breakdown spectroscopy, Inductively coupled plasma, Eutrophication, Spectroscopy, 0105 earth and related environmental sciences
Abstract: International audience; Total phosphorus (TP) in sediments is an important chemical variable in the study of the extent of eutrophication in water bodies. Two methods, based on Single Pulse (SP) and Double Pulse (DP) Laser-Induced Breakdown Spectroscopy (LIBS), were developed for determining TP in the sediment cores of Brazilian rivers upstream from the Barra Bonita reservoir. TP concentration in the sediments was determined by inductively coupled plasma optical emission spectrometry (ICP OES) on digested samples. Besides, a LIBS system operating in SP and DP mode was used to develop methods for the TP quantification in sediment pellets. In LIBS, the most appropriate wavelength to measure P was at 214.91 nm. The calibration curves showed correlation coefficients of 0.93 and 0.92, limits of detection of 709 mg kg-1 and 349 mg kg-1 for SP and DP LIBS, respectively. The two proposed methods were validated and presented an average percentage error of 14% and 10% for SP and DP LIBS, respectively. The ICP OES, SP and DP LIBS data showed that the most superficial layers of the Piracicaba river, all the sedimentary layers of the Tietê river, and the confluence region present a high concentration of TP, according to Brazilian sediment quality criterion. In conclusion, SP and DP LIBS were confirmed as promising alternative tools to traditional analytical methods for monitoring the TP content in the sediments that come from different hydrographic units. The proposed method using DP LIBS proved more sensitive than SP LIBS, but the SP LIBS method demonstrated enough precision for determining TP in eutrophic river sediments.
Published: 2021
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22. Benefit of the Potential Future Hyperspectral Satellite Sensor (BIODIVERSITY) for Improving the Determination of Water Column and Seabed Features in Coastal Zones

Author: Mireille Guillaume, Malik Chami, Sayoob Vadakke-Chanat, Marion Peirache, Audrey Minghelli, Laboratoire d'Informatique et Systèmes (LIS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Signal et Image (SIIM), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), GSM (GSM), Institut FRESNEL (FRESNEL), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Parc national de Port Cros, ANR-15-ASTR-0019,HypFoM,Analyse du fonds marin par imagerie Hyperspectrale : une approche sub-pixel, prise en compte de modèles de transfert radiatif précis de la colonne d'eau et du fond(2015), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), and Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Geophysics. Cosmic physics, 0211 other engineering and technologies, 02 engineering and technology, 01 natural sciences, seabed mapping, ocean color, Water column, EnMAP, Bathymetry, 14. Life underwater, Computers in Earth Sciences, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Image resolution, TC1501-1800, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, Seabed, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Remote sensing, [SDE.IE]Environmental Sciences/Environmental Engineering, QC801-809, Hyperspectral imaging, Ocean engineering, Colored dissolved organic matter, hyperspectral, 13. Climate action, Ocean color, radiative transfer, Environmental science
Abstract: Most of the studies dealing with seabed mapping from hyperspectral images have been carried out using airborne data although hyperspectral satellite sensors have already been or are planned to be launched for the near future (hyperspectral imager for the coastal ocean (HICO) environmental mapping and analysis program (ENMAP) or BIODIVERSITY). The objective of this study is to evaluate the benefit of a BIODIVERSITY-like sensor to determine the bio-optical properties of the water column, namely the Chlorophyll-a concentration, the suspended particulate matter (SPM) concentration, the absorption coefficient of the colored dissolved organic matter (CDOM), the bathymetry and the composition of the seabed, according to its spatial resolution and spectral resolution and its signal to noise ratio. For this purpose, radiative transfer simulations are analyzed together with remote sensing hyperspectral airborne data acquired above the Porquerolles Island (France). The retrieval performance of all in-water and seabed parameters derived from the inversion of BIODIVERSITY-like data is compared with the performance obtained using ENMAP and HICO spatial and radiometric specifications. It is shown that a BIODIVERSITY-like sensor significantly improves the estimation performance of the water column parameters. Furthermore, BIODIVERSITY-like sensor is highly appropriate for seabed mapping when bottom pixels are composed of pure material (e.g., Sand or Posidonia ) in shallow waters when seabed depth is less than 10 m. Conversely, the performance of the inversion deteriorates when seabed pixels are composed of mixed materials (e.g., Sand mixed with Posidonia ). It is also shown that the concentration of chlorophyll, SPM and CDOM absorption are less sensitive to noise level than depth and seabed abundance.
Published: 2021
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23. In‐situ force measurement during nano‐indentation combined with Laue microdiffraction

Author: Thomas W. Cornelius, Florian Lauraux, Olivier P. Thomas, Oleg Kovalenko, Sarah Yehya, Stéphane Labat, Eugen Rabkin, Jean-Sébastien Micha, Odile Robach, Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Nanostructures et Rayonnement Synchrotron (NRS ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Technion Israel Inst Technol, Dept Mat Sci & Engn, IL-32000 Haifa, Israel, ANR-16-CE92-0024,XMicroFatigue,Etude de l'endommagement en fatigue à l'aide de la microscopie à diffraction Laue des rayons X.(2016), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: 010302 applied physics, In situ, Materials science, INDENTATION, 02 engineering and technology, Nanoindentation, 021001 nanoscience & nanotechnology, 01 natural sciences, force measurement, NANOCRYSTALS, in situ nano‐indentation, 0103 physical sciences, TA401-492, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], LAUE MICRODIFFRACTION, Composite material, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, FORCE MEASUREMENT, 0210 nano-technology, Materials of engineering and construction. Mechanics of materials, Laue microdiffraction, ComputingMilieux_MISCELLANEOUS
Abstract: For the characterization of the mechanical properties of materials the precise measurements of stress‐strain curves is indispensable. In situ nano‐mechanical testing setups, however, may lack the precision either in terms of strain or stress determination. Recently, the custom‐built scanning force microscope SFINX was developed which is compatible with third‐generation synchrotron end‐stations allowing for in situ nano‐mechanical tests in combination with nanofocused synchrotron x‐ray diffraction that is highly sensitive to strain and defects. The usage of a self‐actuating and self‐sensing cantilever tremendously increases the compactness of the system but lacks deflection sensitivity and, thus the force measurement. This deficiency is resolved by in situ monitoring the diffraction peaks of the Si cantilever by Laue microdiffraction during the nano‐indentation of a gold crystal. The orientation and, hence, the deflection of the Si cantilever is deduced from the displacement of the Si Laue spots on the detector giving force accuracies of better than 90 nN. At the same time, the dislocation density in the indented Au crystal is tracked by monitoring the Au Laue spots eventually resulting in complete stress‐dislocation density curves.
Published: 2021
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24. Bandpass NGD TAN of Symmetric H-Tree With Resistorless Lumped-Network

Author: George Chan, Jamel Nebhen, Wenceslas Rahajandraibe, Blaise Ravelo, Sebastien Lallechere, Fayu Wan, Nanjing University of Information Science and Technology (NUIST), Prince Sattam Bin Abdul-Aziz University (PSAU), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Institut Pascal (IP), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national polytechnique Clermont Auvergne (INP Clermont Auvergne), Université Clermont Auvergne (UCA)-Université Clermont Auvergne (UCA), Prince Sattam bin Abdulaziz University, and Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)
Subjects: General Computer Science, Computer science, Topology (electrical circuits), 02 engineering and technology, Impedance parameters, Topology, 01 natural sciences, Microstrip, lumped H-tree, law.invention, symmetric multi-port circuit, Tensorial analysis of networks (TAN), law, 0202 electrical engineering, electronic engineering, information engineering, Kron’s formalism, General Materials Science, Electrical impedance, bandpass negative group delay (NGD), Electronic circuit, 020208 electrical & electronic engineering, 010401 analytical chemistry, General Engineering, 0104 chemical sciences, [SPI.TRON]Engineering Sciences [physics]/Electronics, Inductance, Electrical network, S-parameter modeling, RLC circuit, LC-network passive circuit, resistorless topology, lcsh:Electrical engineering. Electronics. Nuclear engineering, lcsh:TK1-9971
Abstract: International audience; This paper introduces an innovative passive topology of bandpass (BP) negative group delay (NGD) electrical circuit implemented with symmetric H-tree network. The multi-port topology of BP NGD circuit is originally represented by a resistorless H-tree constituted by lumped LC-passive network. Until now, the NGD electronic circuits available in the literature are implemented by two-port circuits which are using either resistive elements or distributed microstrip topologies. In the present investigation, the feasibility of the modelling, design, fabrication and test of unfamiliar BP NGD original H-tree circuits. The main objective of the study is to identify analytically the existence of the BP NGD function with the resistorless H-tree circuit. Because of its simplicity and the analytical equation compactness, the uncommon approach of tensorial analysis of networks (TAN) is used in the paper. After the branch and mesh analyses, the impedance matrix of the resistorless H-tree is elaborated. Hence, the resistorless H-tree equivalent S-matrix is established by means of impedance to scattering matrix transform. The BP NGD analysis in function of the inductance and capacitance parameters constituting the H-tree circuit is presented. Then, the main steps of the BP NGD investigation are described. The existence of BP NGD behavior in function of the adequate transmission parameters is identified by the consideration of the canonical form. To validate the BP NGD behavior, a proof of concept (POC) of LC-network based resistorless and symmetrical tree prototype is designed, fabricated and measured. Comparison results between well-correlated TAN calculation, simulation and experimentation are discussed. INDEX TERMS Tensorial analysis of networks (TAN), Kron's formalism, bandpass negative group delay (NGD), resistorless topology, lumped H-tree, symmetric multi-port circuit, S-parameter modeling, LC-network passive circuit.
Published: 2021
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25. Effect of stress on vacancy formation and diffusion in fcc systems: Comparison between DFT calculations and elasticity theory

Author: Philippe Maugis, Damien Connétable, 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), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Aix-Marseille Université - AMU (FRANCE), 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 Toulon - UTLN (FRANCE), Université Toulouse III - Paul Sabatier (UT3), 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), and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Polymers and Plastics, Matériaux, Elasticity theory, chemistry.chemical_element, Thermodynamics, vacancy, 02 engineering and technology, Thermal diffusivity, DFT, 01 natural sciences, law.invention, Aluminium, law, Vacancy defect, 0103 physical sciences, Perpendicular, [CHIM]Chemical Sciences, Solubility, [PHYS]Physics [physics], 010302 applied physics, Vacancy, elasticity theory, stress effects, Metals and Alloys, fcc systems, Elasticity (physics), 021001 nanoscience & nanotechnology, Crystallographic defect, Electronic, Optical and Magnetic Materials, chemistry, Fcc systems, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Ceramics and Composites, Hydrostatic equilibrium, 0210 nano-technology, Stress effects
Abstract: International audience; This paper discusses the effect of stress on the solubility and diffusivity of vacancies using the elasticity theory of point defects. To support the discussion, results are compared with DFT calculations to verify model accuracy. The particular case of vacancies in aluminum is discussed in detail (DFT-elasticity), while three other metallic fcc systems -- Ni, Cu and Pd -- are discussed through the elasticity approach only. Different types of loading were considered: hydrostatic, multi-axial and shear stresses. In the case of a uni-axial loading, two different directions were investigated: the first along a main crystallographic direction, i.e. [001], and the second perpendicular to the dense plane (111). In order to quantify the effect of stress on diffusivity, the diffusion coefficient of each configuration was expressed for further calculations. By analyzing the symmetry break during the loading process, non-equivalent atomic jumps were identified and diffusion equations obtained. A multi-physic approach was carried out by combining first-principles calculations, to study atomic-scale processes, and a multi-state formalism, to obtain exact diffusion equations. Results show that elasticity accurately captures the effects of stress on vacancy diffusion and solubility and an application method is presented.
Published: 2020
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26. Multistatic estimation of high-frequency radar surface currents in the region of Toulon

Author: Bruno Zakardjian, Yann Ourmieres, Anne Molcard, Dylan Dumas, Anthony Gramoullé, Charles-Antoine Guérin, 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)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), and 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)
Subjects: Drifters, High-frequency radar, surface current, 010504 meteorology & atmospheric sciences, drifters, Surface current, Oceanography, 01 natural sciences, law.invention, Mediterranean sea, Acoustic Doppler current profiler, law, 14. Life underwater, Radar, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, 0105 earth and related environmental sciences, Remote sensing, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 010505 oceanography, Ocean current, Mode (statistics), Shelf circulation, Multistatic, Surface velocity, Current (stream), multistatic, High-Frequency radar, Geology
Abstract: The high-frequency radar coastal network in Toulon operates in multistatic mode for the monitoring of the ocean circulation in the Northwestern Mediterranean Sea. With 2 transmitters and 2 receivers on 3 distant sites, it measures 4 different elliptical components of the surface velocity. We provide a methodology for improved current mapping using this augmented number of available projections and we show some typical results obtained during the year 2019. The validity and the quality of the reconstruction are assessed through comparisons with two types of in situ measurements, namely drifters’ velocities from a dedicated campaign and acoustic Doppler current profiler data from an opportunity oceanographic campaign. The results of these assessments confirm the accuracy of these high-frequency radar measurements and their ability to capture the meso- to submeso-scale variability of the near shelf circulation.
Published: 2020
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27. Point Processes of Non stationary Sequences Generated by Sequential and Random Dynamical Systems

Author: Ana C. Freitas, Jorge Milhazes Freitas, Sandro Vaienti, Mário Magalhães, Centro de Matemática - Universidade do Porto (CMUP), Universidade do Porto, Centre de Physique Théorique - UMR 7332 (CPT), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), CPT - E7 Systèmes dynamiques : théories et applications, Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), and Universidade do Porto = University of Porto
Subjects: Dynamical systems theory, [MATH.MATH-DS]Mathematics [math]/Dynamical Systems [math.DS], Probability (math.PR), Fibered knot, Statistical and Nonlinear Physics, Dynamical Systems (math.DS), 01 natural sciences, Random dynamical systems, Point process, 010305 fluids & plasmas, 0103 physical sciences, Convergence (routing), FOS: Mathematics, Rare events, Statistical physics, Mathematics - Dynamical Systems, 010306 general physics, Mathematics - Probability, Mathematical Physics, Mathematics
Abstract: We give general sufficient conditions to prove the convergence of marked point processes that keep record of the occurrence of rare events and of their impact for non-autonomous dynamical systems. We apply the results to sequential dynamical systems associated to uniformly expanding maps and to random dynamical systems given by fibred Lasota Yorke maps., Comment: arXiv admin note: text overlap with arXiv:1507.00599
Published: 2020
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28. Fast greedy $$\mathcal {C}$$-bound minimization with guarantees

Author: Baptiste Bauvin, Jean-Francis Roy, Cécile Capponi, François Laviolette, éQuipe d'AppRentissage de MArseille (QARMA), Laboratoire d'Informatique et Systèmes (LIS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), and Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)
Subjects: Discrete mathematics, Majority rule, Infinite set, Boosting (machine learning), MathematicsofComputing_GENERAL, 02 engineering and technology, 01 natural sciences, Ensemble learning, 010104 statistics & probability, [INFO.INFO-LG]Computer Science [cs]/Machine Learning [cs.LG], Artificial Intelligence, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Column generation, Minification, Quadratic programming, 0101 mathematics, Finite set, ComputingMilieux_MISCELLANEOUS, Software, Mathematics
Abstract: The$$\mathcal {C}$$C-bound is a tight bound on the true risk of a majority vote classifier that relies on the individual quality and pairwise disagreement of the voters and provides PAC-Bayesian generalization guarantees. Based on this bound, MinCq is a classification algorithm that returns a dense distribution on a finite set of voters by minimizing it. Introduced later and inspired by boosting, CqBoost uses a column generation approach to build a sparse$$\mathcal {C}$$C-bound optimal distribution on a possibly infinite set of voters. However, both approaches have a high computational learning time because they minimize the$$\mathcal {C}$$C-bound by solving a quadratic program. Yet, one advantage of CqBoost is its experimental ability to provide sparse solutions. In this work, we address the problem of accelerating the$$\mathcal {C}$$C-bound minimization process while keeping the sparsity of the solution and without losing accuracy. We present CB-Boost, a computationally efficient classification algorithm relying on a greedy–boosting-based–$$\mathcal {C}$$C-bound optimization. An in-depth analysis proves the optimality of the greedy minimization process and quantifies the decrease of the$$\mathcal {C}$$C-bound operated by the algorithm. Generalization guarantees are then drawn based on already existing PAC-Bayesian theorems. In addition, we experimentally evaluate the relevance of CB-Boost in terms of the three main properties we expect about it: accuracy, sparsity, and computational efficiency compared to MinCq, CqBoost, Adaboost and other ensemble methods. As observed in these experiments, CB-Boost not only achieves results comparable to the state of the art, but also provides$$\mathcal {C}$$C-bound sub-optimal weights with very few computational demand while keeping the sparsity property of CqBoost.
Published: 2020
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29. Detecting the Guttman effect with the help of ordinal correspondence analysis in synchrotron X-ray diffraction data analysis

Author: Daniel Borschneck, Claude Manté, C. Mocuta, R. van den Bogaert, Sophie Cornu, 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)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), 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), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), ANR-10-BLAN-0605,AGRIPED,Caractérisation, quantification et modélistion de l'impact de l'usage des terres sur un processus majeur d'évolution des sols : le lessivage.(2010), and 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)
Subjects: Statistics and Probability, Discrete mathematics, Ordinal Correspondence Analysis, 021103 operations research, Orthogonal polynomials, Synchrotron X-Ray Diffraction, 0211 other engineering and technologies, Detrended Correspondence Analysis, Eigenvalues, Articles, Randomization, 02 engineering and technology, Guttman scale, Table (information), 01 natural sciences, Correspondence analysis, 010104 statistics & probability, [MATH.MATH-ST]Mathematics [math]/Statistics [math.ST], Synchrotron X-rays diffraction, 0101 mathematics, Statistics, Probability and Uncertainty, Eigenvalues and eigenvectors, Mathematics
Abstract: We propose a method for detecting a Guttman effect in a complete disjunctive table [Image: see text] with Q questions. Since such an investigation is a nonsense when the Q variables are independent, we reuse a previous unpublished work about the chi-squared independence test for Burt's tables. Then, we introduce a two-steps method consisting in plugging the first singular vector from a preliminary Correspondence Analysis (CA) of [Image: see text] as a score x into a subsequent singly-ordered Ordinal Correspondence Analysis (OCA) of [Image: see text] . OCA mainly consists in completing x by a sequence of orthogonal polynomials superseding the classical factors of CA. As a consequence, in presence of a pure Guttman effect, we should in principle have that the second singular vector coincide with the polynomial of degree 2, etc. The hybrid decomposition of the Pearson chi-squared statistics (resulting from OCA) used in association with permutation tests makes possible to reveal such relationships, i.e. the presence of a Guttman effect in the structure of [Image: see text] , and to determine its degree - with an accuracy depending on the signal to noise ratio. The proposed method is successively tested on artificial data (more or less noisy), a well-known benchmark, and synchrotron X-ray diffraction data of soil samples.
Published: 2020
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30. Mapping Inversion Domain Boundaries along Single GaN Wires with Bragg Coherent X-ray Imaging

Author: Jerome Carnis, Joël Eymery, Maxime Dupraz, Guillaume Beutier, Marie-Ingrid Richard, Vincent Favre-Nicolin, Tobias U. Schülli, Ni Li, Olivier P. Thomas, Thomas W. Cornelius, Stéphane Labat, Steven J. Leake, Marc Verdier, Nanostructures et Rayonnement Synchrotron (NRS ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Deutsches Elektronen-Synchrotron [Hamburg] (DESY), 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), ANR-11-BS10-0014,MecaNIX,MecaNIX : Mécanique des Nano-objets étudiée In situ par diffraction X: étude in situ des déformations et des défauts (diffraction cohérente des rayons X) au cours d'un chargement mécanique (AFM)(2011), European Project: 8818823(1989), and Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)
Subjects: Diffraction, Materials science, inversion domain boundary, General Physics and Astronomy, Gallium nitride, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Condensed Matter::Materials Science, chemistry.chemical_compound, Planar, polarity, General Materials Science, Image resolution, business.industry, GaN wires, General Engineering, X-ray, Inversion (meteorology), 021001 nanoscience & nanotechnology, 0104 chemical sciences, chemistry, displacement field, ddc:540, Displacement field, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Optoelectronics, coherent X-ray Bragg imaging, 0210 nano-technology, business
Abstract: ACS nano 14(8), 10305-10312 (2020). doi:10.1021/acsnano.0c03775, Gallium nitride (GaN) is of technological importance for a wide variety of optoelectronic applications. Defects in GaN, like inversion domain boundaries (IDBs), significantly affect the electrical and optical properties of the material. We report, here, on the structural configurations of planar inversion domain boundaries inside n-doped GaN wires measured by Bragg coherent X-ray diffraction imaging. Different complex domain configurations are revealed along the wires with a 9 nm in-plane spatial resolution. We demonstrate that the IDBs change their direction of propagation along the wires, promoting Ga-terminated domains and stabilizing into {11̅00}, that is, m-planes. The atomic phase shift between the Ga- and N-terminated domains was extracted using phase-retrieval algorithms, revealing an evolution of the out-of-plane displacement (∼5 pm, at maximum) between inversion domains along the wires. This work provides an accurate inner view of planar defects inside small crystals., Published by Soc., Washington, DC
Published: 2020
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31. Enumerating k-Arc-Connected Orientations

Author: Kolja Knauer, Petru Valicov, Sarah Blind, Laboratoire de Génie Informatique, de Production et de Maintenance (LGIPM), Université de Lorraine (UL), Universitat de Barcelona (UB), Algorithmique, Combinatoire et Recherche Opérationnelle (ACRO), Laboratoire d'Informatique et Systèmes (LIS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Algorithmes, Graphes et Combinatoire (ALGCO), Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier (LIRMM), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), ANR-15-CE40-0009,GraphEn,Enumération dans les graphes et les hypergraphes: algorithmes et complexité(2015), ANR-17-CE40-0015,DISTANCIA,Théorie métrique des graphes(2017), ANR-16-CE40-0009,GATO,Graphes, Algorithmes et TOpologie(2016), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Departament de Matematiques i Informatica, Universitat de Barcelona, and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)
Subjects: FOS: Computer and information sciences, Discrete Mathematics (cs.DM), General Computer Science, 0102 computer and information sciences, 02 engineering and technology, [INFO.INFO-DM]Computer Science [cs]/Discrete Mathematics [cs.DM], 01 natural sciences, Submodular set function, Combinatorics, [MATH.MATH-CO]Mathematics [math]/Combinatorics [math.CO], FOS: Mathematics, 0202 electrical engineering, electronic engineering, information engineering, Mathematics - Combinatorics, SIMPLE algorithm, Mathematics, Amortized analysis, Applied Mathematics, State (functional analysis), Computer Science Applications, Alpha (programming language), Flow (mathematics), 010201 computation theory & mathematics, Theory of computation, Graph (abstract data type), 020201 artificial intelligence & image processing, Combinatorics (math.CO), Computer Science - Discrete Mathematics
Abstract: We study the problem of enumerating the $k$-arc-connected orientations of a graph $G$, i.e., generating each exactly once. A first algorithm using submodular flow optimization is easy to state, but intricate to implement. In a second approach we present a simple algorithm with $O(knm^2)$ time delay and amortized time $O(m^2)$, which improves over the analysis of the submodular flow algorithm. As ingredients, we obtain enumeration algorithms for the $\alpha$-orientations of a graph $G$ in $O(m^2)$ time delay and for the outdegree sequences attained by $k$-arc-connected orientations of $G$ in $O(knm^2)$ time delay., Comment: 13 pages, 1 Figure, corrected typos
Published: 2020
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32. Networks beyond pairwise interactions: Structure and dynamics

Author: Vito Latora, Federico Battiston, Jean-Gabriel Young, Iacopo Iacopini, Giovanni Petri, Alice Patania, Maxime Lucas, Giulia Cencetti, CPT - E5 Physique statistique et systèmes complexes, Centre de Physique Théorique - UMR 7332 (CPT), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Institut de Biologie du Développement de Marseille (IBDM), and Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Centre National de la Recherche Scientifique (CNRS)
Subjects: FOS: Computer and information sciences, Physics - Physics and Society, Collective behavior, Theoretical computer science, Dynamical systems theory, Complex system, FOS: Physical sciences, General Physics and Astronomy, Physics and Society (physics.soc-ph), 01 natural sciences, 0103 physical sciences, [PHYS.COND.CM-SM]Physics [physics]/Condensed Matter [cond-mat]/Statistical Mechanics [cond-mat.stat-mech], 010306 general physics, ComputingMilieux_MISCELLANEOUS, Topology (chemistry), Social and Information Networks (cs.SI), Physics, Structure (mathematical logic), 010308 nuclear & particles physics, Computer Science - Social and Information Networks, Disordered Systems and Neural Networks (cond-mat.dis-nn), Condensed Matter - Disordered Systems and Neural Networks, Nonlinear Sciences - Adaptation and Self-Organizing Systems, Variety (cybernetics), Social dynamics, FOS: Biological sciences, Quantitative Biology - Neurons and Cognition, Neurons and Cognition (q-bio.NC), Pairwise comparison, Adaptation and Self-Organizing Systems (nlin.AO)
Abstract: The complexity of many biological, social and technological systems stems from the richness of the interactions among their units. Over the past decades, a great variety of complex systems has been successfully described as networks whose interacting pairs of nodes are connected by links. Yet, in face-to-face human communication, chemical reactions and ecological systems, interactions can occur in groups of three or more nodes and cannot be simply described just in terms of simple dyads. Until recently, little attention has been devoted to the higher-order architecture of real complex systems. However, a mounting body of evidence is showing that taking the higher-order structure of these systems into account can greatly enhance our modeling capacities and help us to understand and predict their emerging dynamical behaviors. Here, we present a complete overview of the emerging field of networks beyond pairwise interactions. We first discuss the methods to represent higher-order interactions and give a unified presentation of the different frameworks used to describe higher-order systems, highlighting the links between the existing concepts and representations. We review the measures designed to characterize the structure of these systems and the models proposed in the literature to generate synthetic structures, such as random and growing simplicial complexes, bipartite graphs and hypergraphs. We introduce and discuss the rapidly growing research on higher-order dynamical systems and on dynamical topology. We focus on novel emergent phenomena characterizing landmark dynamical processes, such as diffusion, spreading, synchronization and games, when extended beyond pairwise interactions. We elucidate the relations between higher-order topology and dynamical properties, and conclude with a summary of empirical applications, providing an outlook on current modeling and conceptual frontiers., Accepted for publication in Physics Reports. 109 pages, 47 figures
Published: 2020
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33. The binomial equivalence classes of finite words

Author: Marie Lejeune, Michel Rigo, Matthieu Rosenfeld, Laboratoire d'Informatique et Systèmes (LIS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Algorithmique, Combinatoire et Recherche Opérationnelle (ACRO), and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: FOS: Computer and information sciences, Discrete Mathematics (cs.DM), Binomial (polynomial), Formal Languages and Automata Theory (cs.FL), General Mathematics, Computer Science - Formal Languages and Automata Theory, 0102 computer and information sciences, 02 engineering and technology, [INFO.INFO-DM]Computer Science [cs]/Discrete Mathematics [cs.DM], 01 natural sciences, Combinatorics, ComputingMethodologies_SYMBOLICANDALGEBRAICMANIPULATION, Subsequence, FOS: Mathematics, 0202 electrical engineering, electronic engineering, information engineering, Mathematics - Combinatorics, Computer Science::General Literature, ComputingMilieux_MISCELLANEOUS, Binomial coefficient, Mathematics, Computer Science::Information Retrieval, Context-free language, Astrophysics::Instrumentation and Methods for Astrophysics, Computer Science::Computation and Language (Computational Linguistics and Natural Language and Speech Processing), Combinatorics on words, TheoryofComputation_MATHEMATICALLOGICANDFORMALLANGUAGES, 010201 computation theory & mathematics, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, 020201 artificial intelligence & image processing, Combinatorics (math.CO), Nilpotent group, Computer Science::Formal Languages and Automata Theory, Word (group theory), Computer Science - Discrete Mathematics
Abstract: International audience; Two finite words [Formula: see text] and [Formula: see text] are [Formula: see text]-binomially equivalent if, for each word [Formula: see text] of length at most [Formula: see text], [Formula: see text] appears the same number of times as a subsequence (i.e., as a scattered subword) of both [Formula: see text] and [Formula: see text]. This notion generalizes abelian equivalence. In this paper, we study the equivalence classes induced by the [Formula: see text]-binomial equivalence. We provide an algorithm generating the [Formula: see text]-binomial equivalence class of a word. For [Formula: see text] and alphabet of [Formula: see text] or more symbols, the language made of lexicographically least elements of every [Formula: see text]-binomial equivalence class and the language of singletons, i.e., the words whose [Formula: see text]-binomial equivalence class is restricted to a single element, are shown to be non-context-free. As a consequence of our discussions, we also prove that the submonoid generated by the generators of the free nil-[Formula: see text] group (also called free nilpotent group of class [Formula: see text]) on [Formula: see text] generators is isomorphic to the quotient of the free monoid [Formula: see text] by the [Formula: see text]-binomial equivalence.
Published: 2020
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34. 3D Perception and Augmented Reality Developments in Underwater Robotics for Ocean Sciences

Author: Lorenzo Brignone, Aurélien Arnaubec, Jan Opderbecke, Claire Dune, Matheus Laranjeira, Département Systèmes Sous-Marins - IFREMER, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire Conception des Systèmes Mécaniques et Robotiques - EA 7398 (COSMER), Université de Toulon (UTLN), and Université de Toulon -IUT de Toulon (UTLN)
Subjects: Computer science, media_common.quotation_subject, Terrain, 02 engineering and technology, Virtual reality, Underwater robotics, Remotely operated underwater vehicle, 01 natural sciences, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Underwater augmented reality, Human–computer interaction, [INFO.INFO-AU]Computer Science [cs]/Automatic Control Engineering, Perception, 0202 electrical engineering, electronic engineering, information engineering, [INFO.INFO-RB]Computer Science [cs]/Robotics [cs.RO], 14. Life underwater, ComputingMilieux_MISCELLANEOUS, media_common, 3D visual terrain model, business.industry, 010401 analytical chemistry, Robotics, General Medicine, Mixed reality, 0104 chemical sciences, Operator assistance, 13. Climate action, 020201 artificial intelligence & image processing, Augmented reality, Artificial intelligence, business, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract: Purpose of Review This paper addresses the benefits and challenges of mixed reality (MR) for the exploration of deep-sea environments with remotely operated vehicles. The approach is twofold: virtual reality (VR) let the scientist explore the environment via a visual 3D model, overcoming limitations of local perception. Augmented reality (AR) concepts are designed in order to improve environment perception and interaction. Recent Findings The key to such concepts is the implementation of 3D visual geo-referenced terrain models from the imaging feedback gathered by the vehicle exploring its unknown surroundings. Image processing, underwater vehicle navigation, and user-friendly displays for robotic intervention are addressed in an integrated concept. A broad development programme carried out at the French Institute for Ocean Science, IFREMER, is described and illustrates technical topics and use cases. Summary 3D perception derived from camera vision is shown to enable AR concepts that will significantly improve remote exploration and intervention in unknown natural environments. Cumulative geo-referenced 3D model building is in the process of being taken to reliable functioning in real-world underwater applications, accomplishing a milestone change in the capacity to view and understand the obscure and inaccessible deep-sea world.
Published: 2020
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35. Reviews and syntheses: Bacterial bioluminescence – ecology and impact in the biological carbon pump

Author: Séverine Martini, Lisa Tanet, Laurie Casalot, Christian Tamburini, 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), This research has been supported by a doctoral grant 'Région Sud' and the TANGRAM Architectes agency. The project leading to this publication has received funding from the European FEDER Fund (grant no. 1166-39417). We gratefully acknowledge support from CNRS (project EC2CO 'HEMERA')., and 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)
Subjects: lcsh:Life, 010402 general chemistry, 01 natural sciences, 03 medical and health sciences, Marine bacteriophage, Symbiosis, lcsh:QH540-549.5, Bioluminescence, 14. Life underwater, Ecology, Evolution, Behavior and Systematics, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 030304 developmental biology, Earth-Surface Processes, Marine snow, Trophic level, 0303 health sciences, biology, 010405 organic chemistry, 030306 microbiology, Ecology, lcsh:QE1-996.5, Bioluminescent bacteria, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, 0104 chemical sciences, lcsh:Geology, lcsh:QH501-531, 13. Climate action, Digestive tract, lcsh:Ecology, Bacteria, [SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis
Abstract: Around thirty species of marine bacteria can emit light, a critical characteristic in the oceanic environment where the major part is deprived of sunlight. In this article, we first review current knowledge on bioluminescent bacteria symbiosis in light organs. Then, focusing on gut-associated bacteria, we highlight that recent works, based on omics methods, confirm previous claims about the prominence of bioluminescent bacterial species in fish guts. Such host-symbiont relationships are relatively well established and represent important knowledge in the bioluminescence field. However, the consequences of bioluminescent bacteria continuously released from light organ and through the digestive tracts to the seawater have been barely taken into account at the ecological and biogeochemical level. For too long neglected, we propose to consider the role of bioluminescent bacteria, and to reconsider the biological carbon pump taking into account the bioluminescence effect (bioluminescence shunt hypothesis). Indeed, it has been shown that marine snow and fecal pellets are often luminous due to microbial colonization, which makes them a visual target. These luminous particles seem preferentially consumed by organisms of higher trophic levels in comparison to non-luminous ones. As a consequence, the sinking rate of consumed particles could be either increased (due to repackaging) or reduced (due to sloppy feeding or coprophagy/coprorhexy) which can imply a major impact on global biological carbon fluxes. Finally, we propose a strategy, at a worldwide scale, relying on recently developed instrumentation and methodological tools to quantify the impact of bioluminescent bacteria in the biological carbon pump.
Published: 2020
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36. Rubik Gaussian-based patterns for dynamic texture classification

Author: Frédéric Bouchara, Thanh Phuong Nguyen, Thanh Tuan Nguyen, Signal et Image (SIIM), Laboratoire d'Informatique et Systèmes (LIS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: business.industry, Computer science, Gaussian, [INFO.INFO-CV]Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV], Pattern recognition, 02 engineering and technology, [INFO.INFO-DM]Computer Science [cs]/Discrete Mathematics [cs.DM], 01 natural sciences, Thresholding, symbols.namesake, Discriminative model, Artificial Intelligence, 0103 physical sciences, Signal Processing, 0202 electrical engineering, electronic engineering, information engineering, symbols, 020201 artificial intelligence & image processing, Computer Vision and Pattern Recognition, Artificial intelligence, Invariant (mathematics), 010306 general physics, business, Software
Abstract: International audience; Illumination, noise, and changes of environments, scales negatively impact on encoding chaotic motions for dynamic texture (DT) representation. This paper proposes a new method to overcome those issues by addressing the following novel concepts. First, different Gaussian-based kernels are taken into account as an effective filtered pre-processing with low computational cost to point out robust and invariant features. Second, a discriminative operator, named Local Rubik-based Pattern (LRP), is introduced to adequately capture both shape and motion cues of DTs by proposing a new concept of complemented components together with an effective encoding method. In addition, it also addresses a novel thresholding to take into account rich spatio-temporal relationships extracted from a new model of neighborhood supporting region. Finally, an efficient framework for DT description is presented by exploiting operator LRP for encoding various instances of Gaussian-based volumes in order to form a robust descriptor against noise, changes of illumination, scale, and environment. Experiments for DT classification on benchmark datasets have authenticated the interest of our proposal.
Published: 2020
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37. Low-Pass NGD Voice Signal Sensoring With Passive Circuit

Author: Wenceslas Rahajandraibe, Blaise Ravelo, Fayu Wan, Zhongzhu Yuan, Junxiang Ge, Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Signal processing, Computer science, Microphone, Low-pass filter, 010401 analytical chemistry, Filter (signal processing), computer.software_genre, 01 natural sciences, Raised-cosine filter, Signal, 0104 chemical sciences, Speech enhancement, [SPI]Engineering Sciences [physics], Electronic engineering, Waveform, Electrical and Electronic Engineering, Audio signal processing, Instrumentation, computer, ComputingMilieux_MISCELLANEOUS, Group delay and phase delay
Abstract: Nowadays, the speech signal processing is still challenging with the multimedia ubiquity. Classical signal processing techniques as filtering were developed for the speech enhancement to overcome unintentional effects as the propagation channel. However, the delay effect remains an open challenge for audio signal processing engineers. A voice/song signal (VSS) prediction is investigated theoretically and experimentally in this paper. This VSS engineering allows to predict an arbitrary waveform signal by using a lowpass negative group delay (NGD) function. This outstanding function presents the VSS advance properties when its parameters are matched with the operated signals. This NGD engineering analytical approach is described with the audio signal processing. The low-pass NGD analysis and property are deeply investigated with two NGD RC-and RL-passive cells. NGD transient study is performed with parametric analytical signals presenting raised cosine waveform. The introduced VSS NGD sensoring is verified with experimental real-time tests of microphone VSS generator. VSS time-advance of approximately 50 μs was observed with a good agreement between simulations and measurements.
Published: 2020
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38. Global database of ratios of particulate organic carbon to thorium-234 in the ocean: improving estimates of the biological carbon pump

Author: V. Puigcorbé, P. Masqué, F. A. C. Le Moigne, School of Natural Sciences and Centre for Marine Ecosystems Research, Edith Cowan University, EDITH COWAN UNIVERSITY-EDITH COWAN UNIVERSITY, Universitat Autònoma de Barcelona (UAB), 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), and 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)
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, Flux, chemistry.chemical_element, computer.software_genre, 01 natural sciences, Carbon cycle, Water column, Settling, Photic zone, 14. Life underwater, lcsh:Environmental sciences, 0105 earth and related environmental sciences, lcsh:GE1-350, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Total organic carbon, Database, 010604 marine biology & hydrobiology, lcsh:QE1-996.5, Snow, lcsh:Geology, chemistry, 13. Climate action, General Earth and Planetary Sciences, Environmental science, computer, Carbon
Abstract: The ocean's biological carbon pump (BCP) plays a major role in the global carbon cycle. A fraction of the photosynthetically fixed organic carbon produced in surface waters is exported below the sunlit layer as settling particles (e.g., marine snow). Since the seminal works on the BCP, global estimates of the global strength of the BCP have improved but large uncertainties remain (from 5 to 20 Gt C yr−1 exported below the euphotic zone or mixed-layer depth). The 234Th technique is widely used to measure the downward export of particulate organic carbon (POC). This technique has the advantage of allowing a downward flux to be determined by integrating the deficit of 234Th in the upper water column and coupling it to the POC∕234Th ratio in sinking particles. However, the factors controlling the regional, temporal, and depth variations of POC∕234Th ratios are poorly understood. We present a database of 9318 measurements of the POC∕234Th ratio in the ocean, from the surface down to >5500 m, sampled on three size fractions (∼>0.7 µm, ∼1–50 µm, ∼>50 µm), collected with in situ pumps and bottles, and also from bulk particles collected with sediment traps. The dataset is archived in the data repository PANGAEA® under https://doi.org/10.1594/PANGAEA.911424 (Puigcorbé, 2019). The samples presented in this dataset were collected between 1989 and 2018, and the data have been obtained from published papers and open datasets available online. Unpublished data have also been included. Multiple measurements can be found in most of the open ocean provinces. However, there is an uneven distribution of the data, with some areas highly sampled (e.g., China Sea, Bermuda Atlantic Time Series station) compared to some others that are not well represented, such as the southeastern Atlantic, the south Pacific, and the south Indian oceans. Some coastal areas, although in a much smaller number, are also included in this global compilation. Globally, based on different depth horizons and climate zones, the median POC∕234Th ratios have a wide range, from 0.6 to 18 µmol dpm−1.
Published: 2020
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39. High Accuracy Terrain Reconstruction from Point Clouds Using Implicit Deformable Model

Author: Takashi Kanai, Jules Morel, Alexandra Bac, The University of Tokyo (UTokyo), Laboratoire des Sciences de l'Information et des Systèmes (LSIS), Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Paristech ENSAM Aix-en-Provence-Université de Toulon (UTLN)-Aix Marseille Université (AMU), Bac, Alexandra, and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Arts et Métiers Paristech ENSAM Aix-en-Provence-Centre National de la Recherche Scientifique (CNRS)
Subjects: Surface (mathematics), Convection, Implicit function, Point cloud, Deformable model, 020207 software engineering, Geometry, Terrain, Deep learning, 02 engineering and technology, 010501 environmental sciences, 15. Life on land, [INFO.INFO-CG]Computer Science [cs]/Computational Geometry [cs.CG], 01 natural sciences, Article, Lidar, Data point, [INFO.INFO-CG] Computer Science [cs]/Computational Geometry [cs.CG], Partition of unity, Implicit surface, 0202 electrical engineering, electronic engineering, information engineering, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: Few previous works have studied the modeling of forest ground surfaces from LiDAR point clouds using implicit functions. [10] is a pioneer in this area. However, by design this approach proposes over-smoothed surfaces, in particular in highly occluded areas, limiting its ability to reconstruct fine-grained terrain surfaces. This paper presents a method designed to finely approximate ground surfaces by relying on deep learning to separate vegetation from potential ground points, filling holes by blending multiple local approximations through the partition of unity principle, then improving the accuracy of the reconstructed surfaces by pushing the surface towards the data points through an iterative convection model.
Published: 2020

40. Magnetic resonance probing of ferroelectricity and magnetism in metal-organic frameworks

Author: Naresh S. Dalal, Nandita Abhyankar, Sylvain Bertaina, Maylis Orio, Florida State University [Tallahassee] (FSU), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires de Marseille (ISM2), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Magnetism, FOS: Physical sciences, chemistry.chemical_element, 02 engineering and technology, Manganese, 010402 general chemistry, 01 natural sciences, law.invention, Spin probe, chemistry.chemical_compound, Condensed Matter - Strongly Correlated Electrons, law, medicine, Formate, Electron paramagnetic resonance, Condensed Matter - Materials Science, Strongly Correlated Electrons (cond-mat.str-el), medicine.diagnostic_test, Materials Science (cond-mat.mtrl-sci), Magnetic resonance imaging, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Ferroelectricity, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, chemistry, Physical chemistry, Metal-organic framework, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el], 0210 nano-technology
Abstract: International audience; We employ electron paramagnetic resonance (EPR) of the spin probe Mn 2þ to study the paraelectric À ferroelectric transition in Dimethylammonium Manganese Formate (DMMnF) and Mn 2þ-doped Dimethylammonium Zinc Formate (DMZnF), which are considered model metal À organic frameworks (MOF) with a Pb-free perovskite architecture. In DMMnF, we study the variation of the Mn 2þ EPR line shape and intensity at the X-band ($9.4 GHz) and over 80 to 300 K, and we show the absence of magnetoelectric coupling at the ferro-electric transition. At the antiferromagnetic transition in DMMnF, we detect a magnetoelectric coupling caused by weak ferromagnetism in the AFM phase. In DMZnF, EPR spectra of the Mn 2þ probe combined with DFT show that the crystal field is predominantly determined by the Dimethylammonium (DMA þ) cations. ARTICLE HISTORY
Published: 2022
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41. Pairing and superconductivity in quasi-one-dimensional flat-band systems: Creutz and sawtooth lattices

Author: Si Min Chan, B. Grémaud, G. G. Batrouni, Centre de Physique Théorique - UMR 7332 (CPT), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), CPT - E6 Nanophysique, and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Superconductivity (cond-mat.supr-con), [PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con], Condensed Matter - Superconductivity, High Energy Physics::Lattice, 0103 physical sciences, FOS: Physical sciences, 010306 general physics, 01 natural sciences, 010305 fluids & plasmas
Abstract: International audience; We study the pairing and superconducting properties of the attractive Hubbard model in two quasi one-dimensional topological lattices: the Creutz and sawtooth lattices. They share two peculiar properties: each of their band structures exhibits a flat band with a non-trivial winding number. The difference, however, is that only the Creutz lattice is genuinely topological, owing to a chiral (sub-lattice) symmetry, resulting in a quantized winding number and zero energy edge modes for open boundary conditions. We use mean field and exact density matrix renormalization group in our work. Our three main results are: (a) For both lattice systems, the superconducting weight, $D_s$, is linear in the coupling strength, $U$, for low values of $U$; (b) for small $U$, $D_s$ is proportional to the quantum metric for the Creutz system but not for the sawtooth system because its sublattices are not equivalent; (c) conventional BCS mean field is not appropriate for such systems with inequivalent sublattices. We show that, for a wide range of densities and coupling strengths, these systems are very well described by a full multi-band mean field method where the pairing parameters and the local particle densities on the inequivalent sublattices are variational mean field parameters.
Published: 2022
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42. Patterns of mesozooplankton community composition and vertical fluxes in the global ocean

Author: Rainer Kiko, Lars Stemmann, Kissao Gnandi, Manoela C. Brandão, Yawouvi Dodji Soviadan, Jean-Olivier Irisson, Sakina-Dorothée Ayata, Jean-Louis Jamet, Fabio Benedetti, Fabien Lombard, 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), Laboratoire d'océanographie de Villefranche (LOV), 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), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Lomé [Togo], ANR-19-MPGA-0012,TAD,Tropical Atlantic Deoxygenation: gateway dynamics, feedback mechanisms and ecosystem impacts(2019), 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), Processus et interactions de fine échelle océanique (PROTEO), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), 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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut Universitaire de France (IUF), and Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.)
Subjects: 0106 biological sciences, 010504 meteorology & atmospheric sciences, Oxygen Minimum Zone, Particle flux, Aquatic Science, 01 natural sciences, Zooplankton, Latitude, Abundance (ecology), Mesopelagic, Organic matter, 14. Life underwater, Biological carbon pump, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, chemistry.chemical_classification, geography, Biomass (ecology), geography.geographical_feature_category, 010604 marine biology & hydrobiology, Epipelagic, Attenuation rates, Geology, Community structure, Oceanography, chemistry, Community composition, 13. Climate action, Environmental science, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Oceanic basin
Abstract: International audience; Vertical variations in physical and chemical conditions drive changes in marine zooplankton community composition. In turn, zooplankton communities play a critical role in regulating the transfer of organic matter produced in the surface ocean to deeper layers. Yet, the links between zooplankton community composition and the strength of vertical fluxes of particles remain elusive, especially on a global scale. Here, we provide a comprehensive analysis of variations in zooplankton community composition and vertical particle flux in the upper kilometer of the global ocean. Zooplankton samples were collected across five depth layers and vertical particle fluxes were assessed using continuous profiles of the Underwater Vision Profiler (UVP5) at 57 stations covering seven ocean basins. Zooplankton samples were analysed using a Zooscan and individual organisms were classified into 19 groups for the quantitative analyses. Zooplankton abundance, biomass and vertical particle flux decreased from the surface to 1000 m depth at all latitudes. The zooplankton abundance decrease rate was stronger at sites characterised by oxygen minima (2.kg−1) where most zooplankton groups showed a marked decline in abundance, except the jellyfishes, molluscs, annelids, large protists and a few copepod families. The attenuation rate of vertical particle fluxes was weaker at such oxygen-depleted sites. Canonical redundancy analyses showed that the epipelagic zooplankton community composition depended on the temperature, on the phytoplankton size distribution and the surface large particulate organic matter while oxygen was an additional important factor for structuring zooplankton in the mesopelagic. Our results further suggest that future changes in surface phytoplankton size and taxa composition and mesopelagic oxygen loss might lead to profound shift in zooplankton abundance and community structure in both the euphotic and mesopelagic ocean. These changes may affect the vertical export and hereby the strength of the biological carbon pump.
Published: 2022
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43. Anthropogenic fibres in white clams, Meretrix lyrata, cultivated downstream a developing megacity, Ho Chi Minh City, Viet Nam

Author: Thuy-Chung Kieu-Le, Quoc-Viet Tran, Tran-Nguyen-Sang Truong, Emilie Strady, Ho Chi Minh City University of Technology (HCMUT), 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)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), and 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)
Subjects: animal structures, 010504 meteorology & atmospheric sciences, Microplastic, Bivalve, 010501 environmental sciences, Aquatic Science, Oceanography, 01 natural sciences, Pollution, Bivalvia, Rivers, Vietnam, 13. Climate action, Animals, Humans, Saigon River, Cities, Can Gio mangrove, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, 0105 earth and related environmental sciences
Abstract: International audience; Anthropogenic fibres are an emerging pollutant worldwide. The Can Gio mangrove area is located downstream of the Saigon River, and is characterised by high level of anthropogenic fibres originating from domestic and industrial textile and apparel manufacturing. In this area, biota is thus subjected to a high potential risk of anthropogenic fibre contamination. This study aims to characterise the accumulation of anthropogenic fibres in different tissues, i.e. gills, digestive systems, and remaining tissues, of white clams (Meretrix lyrata) cultivated in the Can Gio beach sand, during a seven-month sampling period. The results showed an average concentration of 3.6 ± 2.1 fibres individual-1 or 2.7 ± 2.4 fibres g-1 ww. Higher fibre accumulation was observed in remaining tissues than in gills and digestive systems, and no temporal variation was observed in all clam tissues. The intake of fibres by humans consuming clams was estimated to be 324 fibres inhabitant-1 yr-1 .
Published: 2022
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44. New high-tech flexible networks for the monitoring of deep-sea ecosystems

Author: Jacopo Aguzzi, Damianos Chatzievangelou, Simone Marini, Emanuela Fanelli, Roberto Danovaro, Sascha Flögel, Nadine Lebris, Francis Juanes, Fabio C. De Leo, Joaquin Del Rio, Laurenz Thomsen, Corrado Costa, Giorgio Riccobene, Cristian Tamburini, Dominique Lefevre, Carl Gojak, Pierre-Marie Poulain, Paolo Favali, Annalisa Griffa, Autun Purser, Danelle Cline, Duane Edgington, Joan Navarro, Sergio Stefanni, Steve D’Hondt, Imants G. Priede, Rodney Rountree, Joan B. Company, Agencia Estatal de Investigación (España), European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Università Politecnica delle Marche [Ancona] (UNIVPM), Department of Marine Science, Polytechnnic University of Marche, Pharmacology, Agricultural Engineering Research Unit, Agricultural Research Council (CRA), 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)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Istituto Nazionale di Geofisica e di Oceanografia Sperimentale (OGS), European Multidisciplinary Seafloor and water column Observatory (EMSO), Istituto di Science Marine (ISMAR ), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Estación Biológica de Doñana (EBD), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Université Montpellier 2 - Sciences et Techniques (UM2), Institute of Marine Sciences / Institut de Ciències del Mar [Barcelona] (ICM), Jacobs University [Bremen], University of Florida [Gainesville] (UF), Stazione Zoologica Anton Dohrn (SZN), Sorbonne Université (SU), University of Victoria [Canada] (UVIC), Istituto Nazionale di Fisica Nucleare, Sezione di Catania (INFN), Università degli studi di Catania = University of Catania (Unict), Division technique INSU/SDU (DTI), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), 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), and Consiglio Nazionale delle Ricerche (CNR)
Subjects: Physics - Instrumentation and Detectors, Monitoring, Traceability, [SDE.MCG]Environmental Sciences/Global Changes, Biodiversity, FOS: Physical sciences, Augmented observatories, 010501 environmental sciences, 01 natural sciences, Mining, Ecosystems, Deep Sea, Abundance (ecology), Environmental Chemistry, Ecosystem, 14. Life underwater, Quantitative Biology - Populations and Evolution, ComputingMilieux_MISCELLANEOUS, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, Trophic level, [SDV.EE]Life Sciences [q-bio]/Ecology, environment, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Abiotic component, business.industry, Environmental resource management, Populations and Evolution (q-bio.PE), Pelagic zone, General Chemistry, Instrumentation and Detectors (physics.ins-det), 13. Climate action, Benthic zone, FOS: Biological sciences, Environmental science, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, business
Abstract: 16 pages, 4 figures, 2 tables, Increasing interest in the acquisition of biotic and abiotic resources from within the deep sea (e.g., fisheries, oil–gas extraction, and mining) urgently imposes the development of novel monitoring technologies, beyond the traditional vessel-assisted, time-consuming, high-cost sampling surveys. The implementation of permanent networks of seabed and water-column-cabled (fixed) and docked mobile platforms is presently enforced, to cooperatively measure biological features and environmental (physicochemical) parameters. Video and acoustic (i.e., optoacoustic) imaging are becoming central approaches for studying benthic fauna (e.g., quantifying species presence, behavior, and trophic interactions) in a remote, continuous, and prolonged fashion. Imaging is also being complemented by in situ environmental-DNA sequencing technologies, allowing the traceability of a wide range of organisms (including prokaryotes) beyond the reach of optoacoustic tools. Here, we describe the different fixed and mobile platforms of those benthic and pelagic monitoring networks, proposing at the same time an innovative roadmap for the automated computing of hierarchical ecological information on deep-sea ecosystems (i.e., from single species’ abundance and life traits to community composition, and overall biodiversity), This work was developed within the framework of the Tecnoterra (ICM-CSIC/UPC) and the following project activities: ARIM (Autonomous Robotic sea-ﬂoor Infrastructure for benthopelagic Monitoring; MartTERA ERA-Net Cofound), ARCHES (Autonomous Robotic Networks to Help Modern Societies; German Helmholtz Association), RESBIO (Grant TEC2017-87861-R; Ministerio de Ciencia, Innovación y Universidades), RESNEP (Grant CTM2017-82991-C2-1-R; Ministerio de Ciencia, Innovacion y Universidades), MERCES (Marine Ecosystem Restoration in Changing European Seas - GA No. 689518), and IDEM (Implementing the MSFD to the Deep Mediterranean Sea, GA No. 11.0661/2017/750680/SUB/ENV.C2)
Published: 2022
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45. The role of coupled DNRA-Anammox during nitrate removal in a highly saline lake

Author: Patricia Bonin, Thomas Hein, Juan José Gómez-Alday, Wolfgang Wanek, Nicolas Valiente, Judith Prommer, Franz Jirsa, 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), and 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)
Subjects: 0106 biological sciences, Pollution, inorganic chemicals, Environmental Engineering, Denitrification, 010504 meteorology & atmospheric sciences, Nitrogen, media_common.quotation_subject, Nitrous Oxide, chemistry.chemical_element, 01 natural sciences, Mesocosm, chemistry.chemical_compound, Nitrate, Ammonium Compounds, Environmental Chemistry, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Waste Management and Disposal, Ecosystem, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, media_common, Nitrates, Chemistry, 010604 marine biology & hydrobiology, Aquatic ecosystem, Nitrous oxide, 6. Clean water, Lakes, 13. Climate action, Anammox, Environmental chemistry, [SDE]Environmental Sciences, Oxidation-Reduction
Abstract: Nitrate (NO3-) removal from aquatic ecosystems involves several microbially mediated processes, including denitrification, dissimilatory nitrate reduction to ammonium (DNRA), and anaerobic ammonium oxidation (anammox), controlled by slight changes in environmental gradients. In addition, some of these processes (i.e. denitrification) may involve the production of undesirable compounds such as nitrous oxide (N2O), an important greenhouse gas. Saline lakes are prone to the accumulation of anthropogenic contaminants, making them highly vulnerable environments to NO3- pollution. The aim of this paper was to investigate the effect of light and oxygen on the different NO3- removal pathways under highly saline conditions. For this purpose, mesocosm experiments were performed using lacustrine, undisturbed, organic-rich sediments from the Petrola Lake (Spain), a highly saline waterbody subject to anthropogenic NO3- pollution. The revised 15N-isotope pairing technique (15N-IPT) was used to determine NO3- sink processes. Our results demonstrate for the first time the coexistence of denitrification, DNRA, and anammox processes in a highly saline lake, and how their contribution was determined by environmental conditions (oxygen and light). DNRA, and especially denitrification to N2O, were the dominant nitrogen (N) removal pathways when oxygen and/or light were present (up to 82%). In contrast, anoxia and darkness promoted NO3- reduction by DNRA (52%), combined with N loss by anammox (28%). Our results highlight the role of coupled DNRA-anammox, which has not yet been investigated in lacustrine sediments. We conclude that anoxia and darkness favored DNRA and anammox processes over denitrification and therefore to restrict N2O emissions to the atmosphere.
Published: 2022
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46. Gauge-invariance in cellular automata

Author: Giuseppe, Di Molfetta, Arrighi, Pablo, Di Molfetta, Giuseppe, Eon, Nathanaël, Duranthon, O., Quantum Computation Structures (QuaCS), Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Méthodes Formelles (LMF), Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Ecole Normale Supérieure Paris-Saclay (ENS Paris Saclay)-CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Ecole Normale Supérieure Paris-Saclay (ENS Paris Saclay), Laboratoire d'Informatique et Systèmes (LIS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), and Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)
Subjects: FOS: Computer and information sciences, Formal Languages and Automata Theory (cs.FL), High Energy Physics::Lattice, FOS: Physical sciences, Computer Science - Formal Languages and Automata Theory, 01 natural sciences, High Energy Physics::Theory, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], 0103 physical sciences, gauge, invariance, [INFO]Computer Science [cs], 010306 general physics, ComputingMilieux_MISCELLANEOUS, Quantum Physics, 010308 nuclear & particles physics, Cellular Automata and Lattice Gases (nlin.CG), High Energy Physics::Phenomenology, Nonlinear Sciences::Cellular Automata and Lattice Gases, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], Computer Science Applications, gauge field theory, Quantum Physics (quant-ph), cellular automaton, Nonlinear Sciences - Cellular Automata and Lattice Gases, Computer Science::Formal Languages and Automata Theory
Abstract: Gauge-invariance is a fundamental concept in Physics -- known to provide mathematical justification for the fundamental forces. In this paper, we provide discrete counterparts to the main gauge theoretical concepts directly in terms of Cellular Automata. More precisely, the notions of gauge-invariance and gauge-equivalence in Cellular Automata are formalized. A step-by-step gauging procedure to enforce this symmetry upon a given Cellular Automaton is developed, and three examples of gauge-invariant Cellular Automata are examined., Comment: This article supersedes arXiv:1802.07644 and arXiv:1908.01229
Published: 2022
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47. Revisited Estimation of Moderate Resolution Sargassum Fractional Coverage Using Decametric Satellite Data (S2-MSI)

Author: Jacques Descloitres, Audrey Minghelli, François Steinmetz, Cristèle Chevalier, Malik Chami, Léo Berline, interaction Clouds Aerosols Radiations - ICARE/AERIS Data and Services Center - UMS 2877 (ICARE), Centre National d'Études Spatiales [Toulouse] (CNES)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Informatique et Systèmes (LIS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), HYGEOS (SARL), 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)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université de Lille, and Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, 010504 meteorology & atmospheric sciences, Science, Sargassum, AFAI, 0211 other engineering and technologies, 02 engineering and technology, 01 natural sciences, ocean color, fractional coverage, MODIS, [SDE]Environmental Sciences, General Earth and Planetary Sciences, 14. Life underwater, Sentinel-2, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences
Abstract: Since 2011, massive stranding of the brown algae Sargassum has regularly affected the coastal waters of the West Caribbean, Brazil and West Africa, leading to significant environmental and socio-economic impacts. The AFAI algal index (Alternative Floating Algae Index) is often used with remote sensing data in order to estimate the Sargassum coverage, and more precisely the AFAI deviation, which consists of the difference between AFAI and AFAI of the Sargassum-free background. In this study, the AFAI deviation is computed using NASA’s 1 km Terra/MODIS (Moderate-Resolution Imaging Spectroradiometer) and ESA/Copernicus’s 20 m Sentinel-2/MSI (Multi Spectral Instrument) for the same sites and at the same time. Both MODIS and MSI AFAI deviations are compared to confirm the relevance of AFAI deviation technique for two very different spatial resolutions. A high coefficient of determination was found, thus confirming a satisfactory downsampling from 20 m (MSI) to 1 km (MODIS). Then, AFAI deviations are used to estimate the fractional coverage of Sargassum (noted FC). A new linear relationship between the MODIS AFAI deviation and FC is established using the dense Sargassum aggregations observed by MSI data. The AFAI deviation is proportional to FC with a factor of proportionality close to 0.08. Finally, it is shown that the factor is dependent on the Sargassum spectral reflectance, submersion or physiological state.
Published: 2021
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48. Long distance particle transport to the central Ionian Sea

Author: Melilotus Thyssen, Anne Petrenko, Stéphanie Barrillon, Léo Berline, Frédéric A. C. Le Moigne, Andrea Doglioli, Boris Espinasse, Francois Carlotti, François Simon-Bot, 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)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), 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 Universitaire Européen de la Mer (IUEM), and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO)
Subjects: Mediterranean climate, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, QE1-996.5, geography, Water mass, geography.geographical_feature_category, Ecology, 010504 meteorology & atmospheric sciences, Geology, Particle (ecology), 01 natural sciences, Salinity, Oceanography, Life, 13. Climate action, Ocean gyre, Anticyclone, QH501-531, [SDE]Environmental Sciences, 14. Life underwater, Transect, QH540-549.5, Channel (geography), 0105 earth and related environmental sciences
Abstract: Together with T–S properties, particle abundance in situ measurements are useful to discriminate water masses and derive circulation patterns. In the upper layers of the Ionian Sea, the fresher Atlantic Waters (AW) recently crossing the Sicily Channel meet the resident and saltier AW, which circulated cyclonically in the eastern basin and modified after evaporation and eventually cooling. In May 2017, during the PEACETIME cruise, fluorescence and particle abundance sampled at high resolution revealed unexpected heterogeneity in the central Ionian Sea. Surface salinity measurements, together with altimetry-derived and hull-mounted acoustic Doppler current profiler (ADCP) currents, describe a zonal pathway of AW entering the Ionian Sea, consistent with the so-called cyclonic mode in the North Ionian Gyre. The ION-Tr transect, located between 19–20∘ E at approximately 36∘ N, turned out to be at the crossroads of three water masses, mostly coming from the west, north and an isolated anticyclonic eddy northeast of ION-Tr. Using Lagrangian numerical simulations, we suggest that the contrast in particle loads along ION-Tr originates from particles transported from these three different water masses. Waters from the west, identified as AW carried by a strong southwestward jet, were moderate in particle load, probably originating from the Sicily Channel. The water mass from the north, carrying abundant particles, probably originated in the northern Ionian Sea, or further away from the south Adriatic Sea. Waters from the eddy, depleted in particles and chl a, may originate from south of the Peloponnese, where the Pelops eddy forms. The central Ionian Sea hence appears as a mosaic area, where waters of contrasted biological history meet. This contrast is particularly clear in spring, when blooming and non-blooming areas co-occur. Interpreting the complex dynamics of physical–biogeochemical coupling from discrete measurements made at isolated stations at sea is a challenge. The combination of multiparametric in situ measurements at high resolution with remote sensing and Lagrangian modeling appears as one adequate way to address this challenge.
Published: 2021
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49. Nanostructured LaFeO3/Si thin films grown by pulsed laser deposition

Author: Łukasz Cieniek, Christian Turquat, Mateusz Jędrusik, Christine Leroux, Agnieszka Kopia, Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), AGH University of Science and Technology [Krakow, PL] (AGH UST), and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010302 applied physics, [PHYS]Physics [physics], Materials science, business.industry, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Electronic, Optical and Magnetic Materials, Pulsed laser deposition, 0103 physical sciences, Optoelectronics, Thin film, 0210 nano-technology, business, Instrumentation
Abstract: The orthorhombic LaFeO3 thin films grown by pulsed laser deposition on silicon showed nano-structuration of their surface and preferential crystallographic exposed facets, depending on the deposition temperature. The LaFeO3 film deposited at 850 °C has two types of grain termination, flat or tip-like, corresponding to two different growth directions, respectively [110] and [200]. However, due to the shape of the termination, the two types of grains expose the same {110} facets. The prepared lanthanum iron oxide films are iron deficient and consequently contains oxygen vacancies, the exact chemical formula being LaFe0.82O3-δ.
Published: 2021
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50. Impact of moderately energetic fine-scale dynamics on the phytoplankton community structure in the western Mediterranean Sea

Author: Roxane Tzortzis, Andrea M. Doglioli, Stéphanie Barrillon, Anne A. Petrenko, Francesco d'Ovidio, Lloyd Izard, Melilotus Thyssen, Ananda Pascual, Bàrbara Barceló-Llull, Frédéric Cyr, Marc Tedetti, Nagib Bhairy, Pierre Garreau, Franck Dumas, Gérald Gregori, 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), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), 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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), 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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Institut Mediterrani d'Estudis Avancats (IMEDEA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Universidad de las Islas Baleares (UIB), Fisheries and Oceans Canada (DFO), Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Service Hydrographique et Océanographique de la Marine (SHOM), Ministère de la Défense, This research has been supported by the Centre National d'Etudes Spatiales (grant no. BC 4500066497)., Centre National D'Etudes Spatiales (France), 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), Processus et interactions de fine échelle océanique (PROTEO), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), 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)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0106 biological sciences, QE1-996.5, front, Ecology, 010504 meteorology & atmospheric sciences, 010604 marine biology & hydrobiology, Geology, 01 natural sciences, Life, fine-scale, QH501-531, phytoplankton, 14. Life underwater, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, QH540-549.5, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Earth-Surface Processes
Abstract: Model simulations and remote sensing observations show that ocean dynamics at fine scales (1–100 km in space, day–weeks in time) strongly influence the distribution of phytoplankton. However, only a few in situ-based studies at fine scales have been performed, and most of them concern western boundary currents which may not be representative of less energetic regions. The PROTEVSMEDSWOT cruise took place in the moderately energetic waters of the western Mediterranean Sea (WMS), in the region south of the Balearic Islands. Taking advantage of nearreal-time satellite information, we defined a sampling strategy in order to cross a frontal zone separating different water masses. Multi-parametric in situ sensors mounted on the research vessel, on a towed vehicle and on an ocean glider were used to sample physical and biogeochemical variables at a high spatial resolution. Particular attention was given to adapting the sampling route in order to estimate the vertical velocities in the frontal area also. This strategy was successful in sampling quasi-synoptically an oceanic area characterized by the presence of a narrow front with an associated vertical circulation. A multiparametric statistical analysis of the collected data identifies two water masses characterized by different abundances of several phytoplankton cytometric functional groups, as well as different concentrations of chlorophyll a and O2. Here, we focus on moderately energetic fronts induced by fine-scale circulation. Moreover, we explore physical–biological coupling in an oligotrophic region. Our results show that the fronts induced by the finescale circulation, even if weaker than the fronts occurring in energetic and nutrient-rich boundary current systems, maintain nevertheless a strong structuring effect on the phytoplankton community by segregating different groups at the surface. Since oligotrophic and moderately energetic regions are representative of a very large part of the world ocean, our results may have global significance when extrapolated., This research has been supported by the Centre National d’Etudes Spatiales (grant no. BC 4500066497).
Published: 2021
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