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5. Rapid Strengthening of Interstitial Free Steel Using Amorphous FeC Thin Films and Induction Heating

Author

Cantergiani, E., Sauvage, X., Scott, C., Weck, A., Microstructure Physics and Metal Forming [MPIE Düsseldorf], Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Groupe de physique des matériaux (GPM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Canmet MATERIALS, and University of Ottawa [Ottawa]

Subjects
Interstitial free (IF) steels, Induction heating, FeC films, Physical Vapor Deposition (PVD), Mechanics of Materials, Mechanical Engineering, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Materials Science, Transmission Electron Microscopy (TEM)
Abstract

International audience; A new process to rapidly obtain high strength interstitial free (IF) steel was investigated. Thin sheets of IF steel were coated on one or both sides with an amorphous FeC film and subjected to a two-step induction heating cycle (1100 ˚C followed by an isothermal hold at 780 ˚C for 2 or 4 minutes) and a rapid quench in water. Tensile mechanical properties were measured and a yield stress of 374 MPa and an ultimate tensile strength of 448 MPa were achieved after 2 minutes of induction heating. After 4 minutes of induction heating, the yield stress and the ultimate tensile strength drop at 206 MPa and 320 MPa respectively. During tensile testing, the specimens induction heated for 2 minutes show Lüdering, which is suppressed when the induction heating is extended to 4 minutes. Vickers microhardness measurements through thickness confirm that higher mechanical properties are obtained after 2 minutes of induction heating. Transmission electron microscopy reveals that strengthening results from dislocations, carbon in solid solution, and the precipitation of nanosized TiC particles. A fine microstructure with an average grain size of 15 μm is preserved after the induction heat treatment.

Published
2022

6. Dual-Phase Steels: The First Family of Advanced High Strength Steels

Author

Irina Pushkareva, Mohamed Gouné, Colin Scott, Julien Teixeira, Sébastien Allain, Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Canmet MATERIALS, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), and Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Metallurgy, 0211 other engineering and technologies, 02 engineering and technology, 021001 nanoscience & nanotechnology, Microstructure, Dual (category theory), [SPI.MAT]Engineering Sciences [physics]/Materials, Martensite, Ferrite (iron), Formability, 0210 nano-technology, Ductility, Composite microstructure, 021102 mining & metallurgy
Abstract

International audience; Dual-Phase steels have been marketed since the early 1990s and are widely used in the sector of automotive and truck construction. They make up the majority of so-called modern or first-generation AHSS (Advanced High Strength Steels). The superior balance between strength, formability and ductility of DP steels comes from their particular composite microstructure, consisting mainly of ferrite and martensite. This article traces first the history of DP steels from their discovery in the 1960s to the most recent industrial developments. It then addresses current knowledge about the link between the microstructure and mechanical properties of these alloys. The mechanisms governing their microstructure morphogenesis are described in a third part. During those discussions, the contributions of metallurgical and micromechanical modeling in DP science shall be highlighted. Finally, the active fields of research and the anticipated developments of DP technologies will be evoked.

Published
2020

7. The Mode of Incorporation of As(-I) and Se(-I) in Natural Pyrite Revisited

Author

Stephan N. Steinmann, Magdalena Murdzek, Dogan Paktunc, Valentina Batanova, Alain Manceau, Olivier Mathon, Pieter Glatzel, Margarita Merkulova, Alexandre Simionovici, Institut des Sciences de la Terre (ISTerre), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), European Synchrotron Radiation Facility (ESRF), Laboratoire de Chimie - UMR5182 (LC), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), CanMet, Environment and Climate Change Canada, Laboratoire de Géophysique Interne et Tectonophysique (LGIT), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Laboratoire Central des Ponts et Chaussées (LCPC)-Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Laboratoire de Géodynamique des Chaines Alpines (LGCA), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut des Sciences de la Terre (ISTerre), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Grenoble Alpes [2020-....] (UGA [2020-....])-Université Gustave Eiffel (UNIV GUSTAVE EIFFEL)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Natural Resources Canada (NRCan), Institut des Sciences de la Terre [2020-….] (ISTerre [2020-….]), and Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel (UNIV GUSTAVE EIFFEL)-Université Grenoble Alpes [2020-....] (UGA [2020-....])

Subjects
inorganic chemicals, Atmospheric Science, chemistry.chemical_element, 010501 environmental sciences, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, DFT, Natural (archaeology), Hydrothermal circulation, Crystal14, Geochemistry and Petrology, [CHIM]Chemical Sciences, Coal, selenium, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Arsenic, 0105 earth and related environmental sciences, Chemistry, business.industry, ab initio, arsenic, [CHIM.CATA]Chemical Sciences/Catalysis, XANES, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, EXAFS, 13. Climate action, Space and Planetary Science, Environmental chemistry, engineering, Sedimentary rock, Pyrite, business, Selenium
Abstract

International audience; Pyrite (FeS2) from coal, sedimentary rocks, and hydrothermal ore deposits generally contains hazardous selenium (Se) and arsenic (As) that are released in natural waters through oxidative dissolution of the host. Knowing how As and Se are structurally incorporated into pyrite has important implication in controlling or preventing their release because trace metal(loid) substitution accelerates the dissolution of pyrite. Previous extended X-ray absorption fine structure (EXAFS) studies have reported that nominally monovalent arsenic clusters at the sulfur site forming As-As pairs at 3.2 Å, whereas monovalent Se does not form Se-Se pairs at this distance for unknown reason. Here, we revisit this question using As and Se K-edge X-ray absorption near-edge structure (XANES) and EXAFS spectroscopy complemented with atomistic calculations. We find that neither As nor Se atoms can be differentiated from S atom at 3.2-3.3 Å, the cluster and dilute model-fits to As-and Se-EXAFS data yielding equivalent least-squares solutions. Thermodynamic calculations of Fe48As3S93 (3.8 wt.% As) and Fe48Se3S93 (4.0 wt.% Se) structures show that the formation of As-As pairs is energetically favorable and the formation of Se-Se pairs unfavorable. Thus, the equilibrium distribution of As and Se predicted by calculation agrees with published EXAFS data. However, this agreement is incidental because EXAFS fits are ambiguous, the same EXAFS spectra being fit indifferently with a cluster and 2 a dilute model. Regarding Se, the dilute model-fit is probably correct since Se-Se pairs are precluded thermodynamically. The situation is less clear for As. The lowest energy atomic arrangement of As in Fe48S93As3 is similar to the local structure of As in arsenopyrite (FeAsS), thus supporting the cluster model. However, the energy gain to total energy provided by the formation of As clusters decreases with decreasing As concentration, making them thermodynamically less favorable below 1.0 wt.%. Determining the actual distribution pattern of As in pyrite is challenging.

Published
2020

8. The Influence of Vanadium Additions on Isothermally Formed Bainite Microstructures in Medium Carbon Steels Containing Retained Austenite

Author

Guillaume Geandier, Fateh Fazeli, Irina Pushkareva, Colin Scott, Matthew Sztanko, Sébastien Allain, Babak Shalchi-Amirkhiz, Canmet MATERIALS, Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Udall Center for Studies in Public Policy, and University of Arizona

Subjects
lcsh:TN1-997, austenite stability, HEXRD, EELS, Materials science, Bainite, Analytical chemistry, chemistry.chemical_element, 02 engineering and technology, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, chemistry.chemical_compound, vanadium microalloying, Ferrite (iron), 0103 physical sciences, General Materials Science, lcsh:Mining engineering. Metallurgy, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Austenite, Precipitation (chemistry), Cementite, Electron energy loss spectroscopy, Metals and Alloys, 021001 nanoscience & nanotechnology, Microstructure, chemistry, bainite, 0210 nano-technology, Carbon
Abstract

The influence of V additions on isothermally formed bainite in medium carbon steels containing retained austenite has been investigated using in-situ high energy X-ray diffraction (HEXRD) and ex-situ electron energy loss spectroscopy (EELS) and energy dispersive X-ray analysis (EDX) techniques in the transmission electron microscope (TEM). No significant impact of V in solid solution on the bainite transformation rate, final phase fractions or on the width of bainite laths was seen for transformations in the range 375&ndash, 430 &deg, C. No strong influence on the dislocation density could be detected, although quantitative analysis was impeded by ferrite tetragonality. A reduction in the carbon content of retained austenite C&gamma, that is not believed to be due to competition with VC or cementite precipitation was observed. No influence of V on the carbon supersaturation in bainitic ferrite Cb could be directly measured, although carbon mass balance calculations suggest Cb slightly increases. A beneficial refinement of blocky MA and a corresponding size effect induced enhancement in austenite stability were found at the lowest transformation temperature. Overall, V additions result in a slight increase in strength levels.

Published
2020

9. Turbulence modeling of a single-phase R134a supersonic ejector. Part 2: Local flow structure and exergy analysis

Author

Sergio Croquer, Sébastien Poncet, Zine Aidoun, Centre d'économie de la Sorbonne (CES), Université Paris 1 Panthéon-Sorbonne (UP1)-Centre National de la Recherche Scientifique (CNRS), Paris School of Economics (PSE), École des Ponts ParisTech (ENPC)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris 1 Panthéon-Sorbonne (UP1)-Centre National de la Recherche Scientifique (CNRS)-École des hautes études en sciences sociales (EHESS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre d'Etudes Prospectives et d'Informations Internationales (CEPII), Centre d'analyse stratégique, Centre de la Technologie de l'Energie de Canmet - Varennes (CTEC), and Ressources Naturelles Canada

Subjects
Exergy, Work (thermodynamics), Turbulence, 020209 energy, Mechanical Engineering, Numerical analysis, Flow (psychology), R134a refrigerant, Turbulence modeling, Thermodynamics, Supersonic ejector, 02 engineering and technology, Building and Construction, Injector, Mechanics, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], law.invention, Exergy analysis, Shock wave, law, 0202 electrical engineering, electronic engineering, information engineering, Environmental science, Working fluid
Abstract

International audience; The present work is the second part of a numerical analysis of a supersonic ejector in single-phase conditions using R134a as the working fluid. In Part 1, a numerical benchmark of some thermodynamic and two-equation turbulence models has been carried out to highlight the numerical model offering the best compromise between accuracy and calculation cost. The validation was achieved by comparing the predicted entrainment ratio with the experimental data of Garcia del Valle et al. In this part, the ejector performance and local flow features are then investigated by a low-Reynolds number k−ω SST model for a wide range of outlet temperatures. Based on these accurate 2D numerical results, a discussion about the validity of the main assumptions usually made by 1D thermodynamic models is then offered. Finally, an exergy analysis is performed at various characteristic sections of the ejector to determine its global efficiency and shed light on the main sources of losses.

Published
2016

10. Chemical Forms of Mercury in Pyrite: Implications for Predicting Mercury Releases in Acid Mine Drainage Settings

Author

Liliana Lefticariu, Magdalena Murdzek, Dogan Paktunc, Rafal Baran, Pieter Glatzel, Alain Manceau, Valentina Batanova, Binoy K. Saikia, Margarita Merkulova, Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), European Synchrotron Radiation Facility (ESRF), CanMet, Environment and Climate Change Canada, Laboratoire de Géophysique Interne et Tectonophysique (LGIT), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Laboratoire Central des Ponts et Chaussées (LCPC)-Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Laboratoire de Réactivité de Surface (LRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
mercury, Sulfide, Iron, chemistry.chemical_element, 010501 environmental sciences, engineering.material, Sulfides, 010502 geochemistry & geophysics, 01 natural sciences, Mining, chemistry.chemical_compound, Environmental Chemistry, Marcasite, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Arsenic, 0105 earth and related environmental sciences, chemistry.chemical_classification, coal, Mercury sulfide, metacinnabar TOC, Pyrite, Metacinnabar, arsenic, General Chemistry, Acid mine drainage, Mercury (element), Carlin-type, marcasite, chemistry, 13. Climate action, Environmental chemistry, engineering, HR-XANES spectroscopy
Abstract

International audience; Pyrite (cubic FeS2) is the most abundant metal sulfide in nature and also the main host mineral of toxic mercury (Hg). Release of mercury in acid mine drainage resulting from the oxidative dissolution of pyrite in coal and ore and rock resulting from mining, processing, waste management, reclamation, and large construction activities is an ongoing environmental challenge. The fate of mercury depends on its chemical forms at the point source, which in turn depends on how it occurs in pyrite. Here, we show that pyrite in coal, sedimentary rocks, and hydrothermal ore deposits can host varying structural forms of Hg which can be identified with high energy-resolution XANES (HR-XANES) spectroscopy. Nominally divalent Hg is incorporated at the Fe site in pyrite from coal and at a marcasite-type Fe site in pyrite from sedimentary rocks. Distinction of the two Hg bonding environments offers a mean to detect microscopic marcasite inclusions (orthorhombic FeS2) in bulk pyrite. In epigenetic pyrite from Carlin-type Au deposit, up to 55 ± 6 at. % of the total Hg occurs as metacinnabar nanoparticles (β-HgSNP), with the remainder being substitutional at the Fe site. Pyritic mercury from Idrija-type Hg deposit (α-HgS ore) is partly divalent and substitutional and partly reduced into elemental form (liquid). Divalent mercury ions, mercury sulfide nanoparticles, and elemental mercury released by the oxidation of pyrite in acid mine drainage settings would have different environmental pathways. Our results could find important applications for designing control strategies of mercury released to land and water in mine-impacted watersheds.

Published
2018

11. Near-infrared spectra of liquid/solid acetylene under Titan relevant conditions and implications for Cassini/VIMS detections

Author

F. C. Wasiak, S. Singh, J. Ph. Combe, S. Le Mouélic, E. Le Menn, T. B. McCord, Vincent Chevrier, Thomas Cornet, L. A. Roe, Canadian Explosives Research Laboratory, CANMET, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Arkansas Center for Space and Planetary Sciences, University of Arkansas [Fayetteville], and Bear Fight Institute

Subjects
Materials science, 010504 meteorology & atmospheric sciences, Infrared, Near-infrared spectroscopy, Analytical chemistry, Infrared spectroscopy, Astronomy and Astrophysics, 01 natural sciences, Astrobiology, chemistry.chemical_compound, symbols.namesake, Acetylene, chemistry, 13. Climate action, Space and Planetary Science, Absorption band, [SDU]Sciences of the Universe [physics], 0103 physical sciences, symbols, Spectral resolution, Titan (rocket family), Spectroscopy, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

Acetylene is thought to be abundant on Titan according to most photochemical models. While detected in the atmosphere, its likely presence at the surface still lacks physical evidence. It is thought that solid acetylene could be a major component of Titan’s lakes shorelines and dry lakebed, detected as the 5 μm-bright deposits with the Cassini/VIMS instrument. Acetylene could also be present under its liquid form as dissolved solids in Titan’s methane–ethane lakes, as emphasized by thermodynamics studies. This paper is devoted to the near-infrared spectroscopy study of acetylene under solid and liquid phases between 1 and 2.2 μm, synthesized in a Titan simulation chamber that is able to reproduce extreme temperature conditions. From experiments, we observed a ∼10% albedo increase between liquid acetylene at 193–188 K and solid acetylene at 93 K. Using the NIR spectroscopy technique we successfully calculated the reflectivity ratio of solid/liquid acetylene as 1.13. The second difference we observed between liquid and solid acetylene is a shift in the major absorption band detected at 1.54 μm, the shift of ∼0.01 μm occurring toward higher wavelength. In order to assess the detectability of acetylene on Titan using the Cassini/VIMS instrument, we adapted our spectra to the VIMS spectral resolution. The spectral band at 1.55 μm and a negative slope at 2.0 μm falls in the Cassini/VIMS atmospheric windows over several VIMS infrared spectels, thus Cassini/VIMS should be able to detect acetylene.

Published
2016

12. Turbulence modeling of a single-phase R134a supersonic ejector. Part 1: Numerical benchmark

Author

Zine Aidoun, Sergio Croquer, Sébastien Poncet, Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Centre de la Technologie de l'Energie de Canmet - Varennes (CTEC), Ressources Naturelles Canada, and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Shock wave, Exergy, Work (thermodynamics), Turbulence, 020209 energy, Mechanical Engineering, Numerical analysis, Turbulence modeling, R134a refrigerant, Thermodynamics, Supersonic ejector, 02 engineering and technology, Building and Construction, Injector, Mechanics, law.invention, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], law, 0202 electrical engineering, electronic engineering, information engineering, Working fluid, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Mathematics
Abstract

International audience; The present work reports a numerical analysis of a supersonic ejector in single-phase conditions using R134a as the working fluid. A numerical benchmark of some thermodynamic and two-equation turbulence models has been carried out to highlight the numerical model offering the best compromise between accuracy and calculation cost. The validation is achieved by comparing the predicted entrainment ratio with the experimental data of Garcia del Valle et al. (2014). The k−ω SST model together with the REFPROP 7.0 database equation appears to be the best combination to predict accurately the ejector performance and capture the shock wave structure. The influence of the outlet temperature, the discussion about the validity of some assumptions made by one-dimensional (1D) models and the exergy analysis within the ejector for the present operating conditions will later be discussed in Part 2 (Croquer et al., 2015).

Published
2016

13. The second Sandia Fracture Challenge: predictions of ductile failure under quasi-static and moderate-rate dynamic loading

Author

Victoria Brinnel, Sheng Wei Chi, Scott Edward Sanborn, Benedikt Döbereiner, Tiantian Zhang, P. D Mattie, Junhe Lian, X. J. Fang, Matthieu Mazière, Ashkan Mahdavi, Thomas Bosiljevac, Napat Vajragupta, Michael Veilleux, Sylvia Feld-Payet, Tomasz Wierzbicki, James E. Warner, John A. Moore, Bruce W. Williams, Keunhwan Pack, Khalil I. Elkhodary, James W. Foulk, Jim Lua, Denis Novokshanov, Arthur A. Brown, Brad L. Boyce, Sharlotte Kramer, Vladislav A. Yastrebov, Krishnaswamy Ravi-Chandar, Yidu Di, Bo Wu, John L. Bignell, A. R. Cerrone, Anthony R. Ingraffea, Aida Nonn, Jožef Predan, G.F. Bomarito, Kyle N. Karlson, B.J. Carter, Pawel Kucharczyk, Edmundo Corona, Sebastian Münstermann, Jacob D. Hochhalter, Shih-Po Lin, M. K. Neilsen, Derek H. Warner, Kristin Dion, J. Zadravec, Jacques Besson, C. H M Simha, Christopher Andrew Jones, Vincent Chiaruttini, Jean-Louis Chaboche, Liang Xue, Andrew J. Gross, Sandia National Laboratories [Albuquerque] (SNL), Sandia National Laboratories - Corporation, Northwestern University [Evanston], American University in Cairo, CANMET, GE Global Research Center, Ostbayerische Technische Hochschule, NASA Langley Research Center [Hampton] (LaRC), Cornell University [New York], Global engineering and materials iNC, ONERA - The French Aerospace Lab [Palaiseau], ONERA-Université Paris Saclay (COmUE), Centre des Matériaux (MAT), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Rheinisch-Westfälische Technische Hochschule Aachen (RWTH), Sandia National Laboratories [Livermore], Massachusetts Institute of Technology (MIT), University of Illinois [Chicago] (UIC), University of Illinois System, University of Maribor, University of Texas at Austin [Austin], Thinkviewer LLC, Massachusetts Institute of Technology. Department of Mechanical Engineering, Wierzbicki, Tomasz, and Pack, Keun Hwan

Subjects
Engineering, metal, Computational Mechanics, 02 engineering and technology, 0203 mechanical engineering, Consistency (statistics), Modelling and Simulation, alloy, Tearing, Computational mechanics, ddc:530, tearing, business.industry, Work (physics), deformation, modeling, Structural engineering, prediction, 021001 nanoscience & nanotechnology, simulation, 020303 mechanical engineering & transports, Mechanics of Materials, Dynamic loading, fracture, Modeling and Simulation, Heat generation, plasticity, Fracture (geology), [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], rupture, Deformation (engineering), 0210 nano-technology, business
Abstract

Ductile failure of structural metals is relevant to a wide range of engineering scenarios. Computational methods are employed to anticipate the critical conditions of failure, yet they sometimes provide inaccurate and misleading predictions. Challenge scenarios, such as the one presented in the current work, provide an opportunity to assess the blind, quantitative predictive ability of simulation methods against a previously unseen failure problem. Rather than evaluate the predictions of a single simulation approach, the Sandia Fracture Challenge relies on numerous volunteer teams with expertise in computational mechanics to apply a broad range of computational methods, numerical algorithms, and constitutive models to the challenge. This exercise is intended to evaluate the state of health of technologies available for failure prediction. In the first Sandia Fracture Challenge, a wide range of issues were raised in ductile failure modeling, including a lack of consistency in failure models, the importance of shear calibration data, and difficulties in quantifying the uncertainty of prediction [see Boyce et al. (Int J Fract 186:5–68, 2014) for details of these observations]. This second Sandia Fracture Challenge investigated the ductile rupture of a Ti–6Al–4V sheet under both quasi-static and modest-rate dynamic loading (failure in ∼∼ 0.1 s). Like the previous challenge, the sheet had an unusual arrangement of notches and holes that added geometric complexity and fostered a competition between tensile- and shear-dominated failure modes. The teams were asked to predict the fracture path and quantitative far-field failure metrics such as the peak force and displacement to cause crack initiation. Fourteen teams contributed blind predictions, and the experimental outcomes were quantified in three independent test labs. Additional shortcomings were revealed in this second challenge such as inconsistency in the application of appropriate boundary conditions, need for a thermomechanical treatment of the heat generation in the dynamic loading condition, and further difficulties in model calibration based on limited real-world engineering data. As with the prior challenge, this work not only documents the ‘state-of-the-art’ in computational failure prediction of ductile tearing scenarios, but also provides a detailed dataset for non-blind assessment of alternative methods., National Science Foundation (U.S.)

Published
2016
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14. Tailoring the mechanical properties of steel sheets using FeC films and diffusion annealing

Author

Elisa Cantergiani, Michel Perez, Ben Lawrence, Colin Scott, Xavier Sauvage, Amélie Fillon, Arnaud Weck, University of Ottawa [Ottawa], Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), University of British Columbia (UBC), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Canmet MATERIALS, Natural Sciences and Engineering Research Council of Canada (NSERC) [STPGP 380944-09], Agence Nationale de la Recherche (ANR) through the GRaCoS Project [ANR-09-BLAN-0412], ArcelorMittal, Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), ANR-09-BLAN-0412,GRACOS,Nouveaux aciers à gradient de propriétés (Graded Composite Steels Design)(2009), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, crystallization, Annealing (metallurgy), 02 engineering and technology, law.invention, Carburizing, law, [CHIM]Chemical Sciences, General Materials Science, titanium, Thin film, Crystallization, Composite material, interstitial-free steel, ultra-low-carbon, metallurgy, 020502 materials, Mechanical Engineering, Metallurgy, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Amorphous solid, Solid solution strengthening, 0205 materials engineering, Mechanics of Materials, Physical vapor deposition, Knoop hardness test, 0210 nano-technology
Abstract

International audience; In this work amorphous FeC films were deposited on thin sheets of interstitial free steel using physical vapor deposition. Annealing treatments were then carried out to diffuse C from the coating into the substrate at temperatures lower than those traditionally used in carburizing treatments. The yield stress was shown to significantly increase with annealing temperature from similar to 120 MPa at 25 degrees C up to a maximum of 300 MPa at 630 degrees C without any significant loss of ductility. At 710 degrees C, a decrease in yield strength was related to the coarsening of carbides inside the IF steel (confirmed by atom probe tomography), and the associated reduction in the matrix solid solution carbon concentration (confirmed by thermoelectric power measurements). The through-thickness carbon diffusion profile was predicted using Fick's law and validated by Knoop hardness measurements. Yield strength predictions were accurate if the crystallization of the FeC film was taken into account as it controls the amount of carbon available to be diffused in the interstitial free steel substrate. (C) 2016 Elsevier B.V. All rights reserved.

Published
2016

15. ACETYLENE ON TITAN’S SURFACE

Author

L. Maltagliati, Roger N. Clark, Vincent Chevrier, Thomas Cornet, Sebastien Rodriguez, S. Le Mouélic, J. P. Combe, T. B. McCord, S. Singh, Canadian Explosives Research Laboratory, CANMET, Department of Earth and Space Sciences [Seattle], University of Washington [Seattle], Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), W.M. Keck Laboratory for Space and Planetary Simulation [Fayetteville], Arkansas Center for Space and Planetary Sciences, University of Arkansas [Fayetteville]-University of Arkansas [Fayetteville], Laboratoire de Planétologie et Géodynamique UMR6112 (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA), and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, 010504 meteorology & atmospheric sciences, Astronomy and Astrophysics, Photochemistry, 01 natural sciences, Methane, chemistry.chemical_compound, symbols.namesake, Acetylene, chemistry, [SDU]Sciences of the Universe [physics], Space and Planetary Science, 0103 physical sciences, symbols, Atmosphere of Titan, Titan (rocket family), 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

International audience

Published
2016

16. Materials Acceleration Platforms (MAPs): Accelerating Materials Research and Development to Meet Urgent Societal Challenges.

Author

Stier SP, Kreisbeck C, Ihssen H, Popp MA, Hauch J, Malek K, Reynaud M, Goumans TPM, Carlsson J, Todorov I, Gold L, Räder A, Wenzel W, Bandesha ST, Jacques P, Garcia-Moreno F, Arcelus O, Friederich P, Clark S, Maglione M, Laukkanen A, Castelli IE, Carrasco J, Cabanas MC, Stein HS, Ozcan O, Elbert D, Reuter K, Scheurer C, Demura M, Han SS, Vegge T, Nakamae S, Fabrizio M, and Kozdras M

Abstract

Climate Change and Materials Criticality challenges are driving urgent responses from global governments. These global responses drive policy to achieve sustainable, resilient, clean solutions with Advanced Materials (AdMats) for industrial supply chains and economic prosperity. The research landscape comprising industry, academe, and government identified a critical path to accelerate the Green Transition far beyond slow conventional research through Digital Technologies that harness Artificial Intelligence, Smart Automation and High Performance Computing through Materials Acceleration Platforms, MAPs. In this perspective, following the short paper, a broad overview about the challenges addressed, existing projects and building blocks of MAPs will be provided while concluding with a review of the remaining gaps and measures to overcome them., (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)

Published
2024
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17. Computational and Machine Learning Methods for CO 2 Capture Using Metal-Organic Frameworks.

Author

Mashhadimoslem H, Abdol MA, Karimi P, Zanganeh K, Shafeen A, Elkamel A, and Kamkar M

Abstract

Machine learning (ML) using data sets of atomic and molecular force fields (FFs) has made significant progress and provided benefits in the fields of chemistry and material science. This work examines the interactions between chemistry and materials computational science at the atomic and molecular scales for metal-organic framework (MOF) adsorbent development toward carbon dioxide (CO 2 ) capture. Herein, a connection will be drawn between atomic forces predicted by ML algorithms and the structures of MOFs for CO 2 adsorption. Our study also takes into account the successes of atomic computational screening in the field of materials science, especially quantum ML, and its relationship to ML algorithms that clarify advancements in the area of CO 2 adsorption by MOFs. Additionally, we reviewed the processes for supplying data to ML algorithms for algorithm training, including text mining from scientific articles, and MOF's formula processing linked to the chemical properties of MOFs. To create ML algorithms for future research, we recommend that the digitization of scientific records can help efficiently synthesize advanced MOFs. Finally, a future vision for developing pioneer MOF synthesis routes for CO 2 capture is presented in this review article.

Published
2024
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18. Microbiological and geochemical characterization of As-bearing tailings and underlying sediments.

Author

Verbuyst BR, Pakostova E, Paktunc D, Bain JG, Finfrock YZ, Saurette EM, Ptacek CJ, and Blowes DW

Abstract

Over the past 100 years, extensive oxidation of As-bearing sulfide-rich tailings from the abandoned Long Lake Gold Mine (Canada) has resulted in the formation of acid mine drainage (pH 2.0-3.9) containing high concentrations of dissolved As (∼400 mg L -1 ), SO 4 2- , Fe and other metals. Dissolved As is predominantly present as As(III), with increased As(V) near the tailings surface. Pore-gas O 2 is depleted to < 1 vol% in the upper 30-80 cm of the tailings profile. The primary sulfides, pyrite and arsenopyrite, are highly oxidized in the upper portions of the tailings. Elevated proportions of sulfide-oxidizing prokaryotes are present in this zone (mean 32.3% of total reads). The tailings are underlain by sediments rich in organic C. Enrichment in δ 34 S-SO 4 in pore-water samples in the organic C-rich zone is consistent with dissimilatory sulfate reduction. Synchrotron-based spectroscopy indicates an abundance of ferric arsenate phases near the impoundment surface and the presence of secondary arsenic sulfides in the organic-C beneath the tailings. The persistence of elevated As concentrations beneath the tailings indicates precipitation of secondary As sulfides is not sufficient to completely remove dissolved As. The oxidation of sulfides and release of As is expected to continue for decades. The findings will inform future remediation efforts and provide a foundation for the long-term monitoring of the effectiveness of the remediation program., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Published
2024
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20. Exploiting redundancy in large materials datasets for efficient machine learning with less data.

Author

Li K, Persaud D, Choudhary K, DeCost B, Greenwood M, and Hattrick-Simpers J

Abstract

Extensive efforts to gather materials data have largely overlooked potential data redundancy. In this study, we present evidence of a significant degree of redundancy across multiple large datasets for various material properties, by revealing that up to 95% of data can be safely removed from machine learning training with little impact on in-distribution prediction performance. The redundant data is related to over-represented material types and does not mitigate the severe performance degradation on out-of-distribution samples. In addition, we show that uncertainty-based active learning algorithms can construct much smaller but equally informative datasets. We discuss the effectiveness of informative data in improving prediction performance and robustness and provide insights into efficient data acquisition and machine learning training. This work challenges the "bigger is better" mentality and calls for attention to the information richness of materials data rather than a narrow emphasis on data volume., (© 2023. The Author(s).)

Published
2023
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21. Freezing and Thawing Resistance of Fine Recycled Concrete Aggregate (FRCA) Mixtures Designed with Distinct Techniques.

Author

Trottier C, de Grazia MT, Macedo HF, Sanchez LFM, Andrade GP, de Souza DJ, Naboka O, Fathifazl G, Nkinamubanzi PC, and Demers A

Abstract

The pressure to use sustainable materials and adopt practices reducing the carbon footprint of the construction industry has risen. Such materials include recycled concrete aggregates (RCA) made from waste concrete. However, concrete made with RCA often presents poor fresh and hardened properties along with a decrease in its durability performance, especially when using its fine fraction (i.e., FRCA). Most studies involving FRCA use direct replacement methods (DRM) to proportion concrete although other techniques are available such as the Equivalent Volume (EV) and Particle Packing Models (PPMs); yet their impact on the durability performance, especially its performance against freezing and thawing (F/T), remains unknown. This work, therefore, appraises the F/T resistance of FRCA mixtures proportioned through various mix proportioning techniques (i.e., DRM, EV and PPMs), produced with distinct crushing processes (i.e., crusher's fines vs. finely ground). The results show that the mix design technique has a significant influence on the FRCA mixture's F/T resistance where PPM-proportioned mixtures demonstrate the best overall performance, exceeding the specified requirements while DRM-proportioned mixtures failed F/T resistance requirements. Moreover, the crushing process plays an important role in the recycled mixtures' cracking behavior under F/T cycles, where less processing leads to fewer cracks while remaining the most sustainable option overall.

Published
2022
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22. Solidification Enhancement in a Multi-Tube Latent Heat Storage System for Efficient and Economical Production: Effect of Number, Position and Temperature of the Tubes.

Author

Li M, Mahdi JM, Mohammed HI, Bokov DO, Mahmoud MZ, Naghizadeh A, Talebizadehsardari P, and Yaïci W

Abstract

Thermal energy storage is an important component in energy units to decrease the gap between energy supply and demand. Free convection and the locations of the tubes carrying the heat-transfer fluid (HTF) have a significant influence on both the energy discharging potential and the buoyancy effect during the solidification mode. In the present study, the impact of the tube position was examined during the discharging process. Liquid-fraction evolution and energy removal rate with thermo-fluid contour profiles were used to examine the performance of the unit. Heat exchanger tubes are proposed with different numbers and positions in the unit for various cases including uniform and non-uniform tubes distribution. The results show that moving the HTF tubes to medium positions along the vertical direction is relatively better for enhancing the solidification of PCM with multiple HTF tubes. Repositioning of the HTF tubes on the left side of the unit can slightly improve the heat removal rate by about 0.2 in the case of p5-u-1 and decreases by 1.6% in the case of p5-u-2. It was found also that increasing the distance between the tubes in the vertical direction has a detrimental effect on the PCM solidification mode. Replacing the HTF tubes on the left side of the unit negatively reduces the heat removal rate by about 1.2 and 4.4%, respectively. Further, decreasing the HTF temperature from 15 °C to 10 and 5 °C can increase the heat removal rate by around 7 and 16%, respectively. This paper indicates that the specific concern to the HTF tube arrangement should be made to improve the discharging process attending free convection impact in phase change heat storage.

Published
2021
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23. A cross scale investigation of galena oxidation and controls on mobilization of lead in mine waste rock.

Author

Bao Z, Al T, Couillard M, Poirier G, Bain J, Shrimpton HK, Finfrock YZ, Lanzirotti A, Paktunc D, Saurette E, Hu Y, Ptacek CJ, and Blowes DW

Abstract

Galena and Pb-bearing secondary phases are the main sources of Pb in the terrestrial environment. Oxidative dissolution of galena releases aqueous Pb and SO 4 to the surficial environment and commonly causes the formation of anglesite (in acidic environments) or cerussite (in alkaline environments). However, conditions prevalent in weathering environments are diverse and different reaction mechanisms reflect this variability at various scales. Here we applied complementary techniques across a range of scales, from nanometers to 10 s of meters, to study the oxidation of galena and accumulation of secondary phases that influence the release and mobilization of Pb within a sulfide-bearing waste-rock pile. Within the neutral-pH pore-water environment, the oxidation of galena releases Pb ions resulting in the formation of secondary Pb-bearing carbonate precipitates. Cerussite is the dominant phase and shannonite is a possible minor phase. Dissolved Cu from the pore water reacts at the surface of galena, forming covellite at the interface. Nanometer scale characterization suggests that secondary covellite is intergrown with secondary Pb-bearing carbonates at the interface. A small amount of the S derived from galena is sequestered with the secondary covellite, but the majority of the S is oxidized to sulfate and released to the pore water., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Published
2021
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24. Thermal Charging Optimization of a Wavy-Shaped Nano-Enhanced Thermal Storage Unit.

Author

Ghalambaz M, Mehryan SAM, Hajjar A, Shdaifat MYA, Younis O, Talebizadehsardari P, and Yaïci W

Subjects
Convection, Hot Temperature, Models, Theoretical, Motion, Nanoparticles, Porosity, Thermodynamics, Coconut Oil chemistry, Copper chemistry
Abstract

A wavy shape was used to enhance the thermal heat transfer in a shell-tube latent heat thermal energy storage (LHTES) unit. The thermal storage unit was filled with CuO-coconut oil nano-enhanced phase change material (NePCM). The enthalpy-porosity approach was employed to model the phase change heat transfer in the presence of natural convection effects in the molten NePCM. The finite element method was applied to integrate the governing equations for fluid motion and phase change heat transfer. The impact of wave amplitude and wave number of the heated tube, as well as the volume concertation of nanoparticles on the full-charging time of the LHTES unit, was addressed. The Taguchi optimization method was used to find an optimum design of the LHTES unit. The results showed that an increase in the volume fraction of nanoparticles reduces the charging time. Moreover, the waviness of the tube resists the natural convection flow circulation in the phase change domain and could increase the charging time.

Published
2021
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25. A DFT study of the interaction between [Cd(H 2 O) 3 ] 2+ and monodentate O-, N-, and S-donor ligands: bond interaction analysis.

Author

da Silva VHM, Quattrociocchi DGS, Stoyanov SR, Carneiro JWM, da Costa LM, and Ferreira GB

Abstract

A series of B3LYP/6-311+G(d,p) calculations of the affinity of monodentate ligands for [Cd(H 2 O) 3 ] 2+ are performed. Three types of ligands containing O (phosphine oxide, lactam, amide, carboxylic acid, ester, ketone, aldehyde, ether, halohydrin, enol, furan), N (thiocyanate, amine, ammonia, azide), and S (thioester, thioketone, thiol, thiophene, disulfide) interacting atoms are investigated. The results show that phosphine oxide has the largest affinity for the cadmium cation due to the polarization of the P=O bond. As the P atom has a large atomic radius, the O atom can polarize the electronic cloud enhancing its amount of electronic charge and favoring the interaction with Cd 2+ . The affinity order found is phosphine oxide > thioester > lactam > amide > carboxylic acid > ester > thioketone > ketone > thiocyanate > amine > ammonia > aldehyde > ether > thiol > thiophene > enol > halohydrin > disulfide > azide > furan ligands. These results were also corroborated by the functional M06-2X. The electronic effects (resonance and induction) of neighboring groups of the interacting atom modulate the strength of metal-ligand binding. For almost all the O-donor ligands the electrostatic component has the same magnitude as the covalent term, while for the N- and S-donor ligands the covalent term is predominant. The polarization term accounts for twice the exchange term as part of the covalent component. The dispersion term varies less than 2 kcal mol -1 for the complexes analyzed. The Pauli repulsion term is correlated with the metal ligand distance, increasing in the compounds with decreased metal-ligand bond length. The charge between the interacting atoms is also strongly correlated with both the interacting strength and the electrostatic interaction component. The natural bond orbital analysis highlights correlations of the bond order, and S and P contributions of the interacting metal-ligand orbital with the coordination strength. Graphical abstract The affinity of 20 monodentate ligands with different functional groups for the [Cd(H 2 O) 3 ] 2+ cation is calculated based on the interaction enthalpy and Gibbs free energy for the substitution of one water molecule from the fully hydrated cation. The affinity is correlated with geometric, electronic, and energetic parameters of the ligands and the complexes as well as with energy decomposition and natural bond order analyses results.

Published
2018
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26. Minimum Burning Pressures of Water-based Emulsion Explosives.

Author

Turcotte R, Badeen CM, and Goldthorp S

Subjects
Emulsions, Explosive Agents analysis, Pressure, Explosive Agents chemistry, Water chemistry
Abstract

This manuscript describes a protocol to measure the minimum pressure required for sustained burning of water-based emulsion explosives. Pumping water-based emulsion explosives for blasting applications can be very hazardous, as demonstrated by a number of pump accidents around the globe in the last decades, including some that resulted in fatalities. In Canada, the recognition of this hazard has led to the development of pumping guidelines that were endorsed by both the explosives industry and the Explosive Regulatory Division of the Canadian government. In these guidelines, it was noted that the minimum burning pressures (MBP) measured in a laboratory would provide a good guide to characterize the behaviour of these products in pumping systems. The same guidelines also call for the design of pump systems that prevent, whenever possible, pressures from exceeding the MBP of the product being pumped. At the time of publication of these guidelines, a methodology existed for measuring such MBP values but it had never been validated to measure the MBP of ammonium nitrate water-based emulsions (AWEs). AWEs are now used much more widely than any other water-based explosives and precursors in on-site bulk loading operations. The Canadian Explosives Research Laboratory (CanmetCERL) has been conducting research over the last ten years to develop a validated testing protocol to measure and interpret representative MBP values for AWEs. The test, as it is performed today, will be described and the critical components will be justified by reference to recent published data. Results of MBP measurements, for a range of AWE products, will be presented. Inclusion of the MBP test in the test standards for the authorization of high explosives in Canada will also be discussed.

Published
2017
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27. A density functional theory investigation of the interaction of the tetraaqua calcium cation with bidentate carbonyl ligands.

Author

Quattrociocchi DG, Meuser MV, Ferreira GB, de M Carneiro JW, Stoyanov SR, and da Costa LM

Abstract

Calcium complexes with bidentate carbonyl ligands are important in biological systems, medicine and industry, where the concentration of Ca 2+ is controlled using chelating ligands. The exchange of two water molecules of [Ca(H 2 O) 6 ] 2+ for one bidentate monosubstituted and homo disubstituted dicarbonyl ligand was investigated using the B3LYP/6-311++G(d,p) method. The ligand substituents NH 2 , OCH 3 , OH, CH 3 , H, F, Cl, CN and NO 2 are functional groups with distinct electron-donating and -withdrawing effects that bond directly to the sp 2 C atom of the carbonyl group. The geometry, charge and energy characteristics of the complexes were analyzed to help understand the effects of substituents, spacer length and chelation. Coordination strength was quantified in terms of the enthalpy and free energy of the exchange reaction. The most negative enthalpies were calculated for the coordination of bidentate ligands containing three to five methylene group spacers between carbonyls. The chelate effect contribution was analyzed based on the thermochemistry. The electronic character of the substituent modulates the strength of binding to the metal cation, as ligands containing electron-donor substituents coordinate stronger than those with electron-acceptor substituents. This is reflected in the geometric (bond length and chelating angle), electronic (atomic charges) and energetic (components of the total interacting energy) characteristics of the complexes. Energy decomposition analysis (EDA)-an approach for partitioning of the energy into its chemical origins-shows that the electrostatic component of the coordination is predominant, and yields relevant contribution of the covalent term, especially for the electron-withdrawing substituted ligands. The chelate effect of the bidentate ligands was noticeable when compared with substitution by two monodentate ligands. Graphical abstract The affinity of 18 bidentate carbonyl ligands toward the [Ca(H 2 O) 4 ] 2+ cation is evaluated in terms of energetic, geometric and electronic parameters of the isolated ligands and the substituted aqua complexes. The electronic effects-inductive and mesomeric-intrinsic to the molecular structure of each ligand are found to modulate the strength of the metal-ligand interaction. The effects of polysubstitution, chelation and the length of the alkyl spacers between the anchor points of the ligand are also analyzed.

Published
2017
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28. New Opportunity for in Situ Exsolution of Metallic Nanoparticles on Perovskite Parent.

Author

Sun YF, Zhang YQ, Chen J, Li JH, Zhu YT, Zeng YM, Amirkhiz BS, Li J, Hua B, and Luo JL

Abstract

One of the main challenges for advanced metallic nanoparticles (NPs) supported functional perovskite catalysts is the simultaneous achievement of a high population of NPs with uniform distribution as well as long-lasting high performance. These are also the essential requirements for optimal electrode catalysts used in solid oxide fuel cells and electrolysis cells (SOFCs and SOECs). Herein, we report a facile operando manufacture way that the crystal reconstruction of double perovskite under reducing atmosphere can spontaneously lead to the formation of ordered layered oxygen deficiency and yield segregation of massively and finely dispersed NPs. The real-time observation of this emergent process was performed via an environmental transmission electron microscope. Density functional theory calculations prove that the crystal reconstruction induces the loss of coordinated oxygen surrounding B-site cations, serving as the driving force for steering fast NP growth. The prepared material shows promising capability as an active and stable electrode for SOFCs in various fuels and SOECs for CO2 reduction. The conception exemplified here could conceivably be extended to fabricate a series of supported NPs perovskite catalysts with diverse functionalities.

Published
2016
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