37 results on '"CANMET"'
Search Results
2. International Round-Robin Study on Thermoelectric Transport Properties of n-type Half-Heusler from 300 K to 773 K
- Author
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Tseng, Yu [CANMET Materials, Hamiliton, ON (Canada)]
- Published
- 2015
- Full Text
- View/download PDF
3. Thermodynamic effects of calcium and iron oxides on crystal phase formation in synthetic gasifier slags containing from 0 to 27wt.% V2O3
- Author
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Hughes, Robin [Canmet ENERGY, Ottawa, ON (Canada)]
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- 2014
- Full Text
- View/download PDF
4. Rapid Strengthening of Interstitial Free Steel Using Amorphous FeC Thin Films and Induction Heating
- Author
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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]
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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.
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- 2022
5. The Mode of Incorporation of As(-I) and Se(-I) in Natural Pyrite Revisited
- Author
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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-....])
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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
6. The Influence of Vanadium Additions on Isothermally Formed Bainite Microstructures in Medium Carbon Steels Containing Retained Austenite
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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
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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 °, 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
7. Gasification behavior of carbon residue in bed solids of black liquor gasifier
- Author
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Wang, Jinsheng [CANMET Energy Technology Centre, Natural Resources (Canada)]
- Published
- 2008
- Full Text
- View/download PDF
8. Upper explosive limit of dusts: Experimental evidence for its existence under certain circumstances
- Author
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Mintz, K [CANMET, Energy, Mines, and Resources Canada, Ottawa, Ontario (Canada). Mining Research Labs.]
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- 1993
- Full Text
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9. Chemical Forms of Mercury in Pyrite: Implications for Predicting Mercury Releases in Acid Mine Drainage Settings
- Author
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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)
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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
10. The second Sandia Fracture Challenge: predictions of ductile failure under quasi-static and moderate-rate dynamic loading
- Author
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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
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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
- Full Text
- View/download PDF
11. ACETYLENE ON TITAN’S SURFACE
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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)
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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
12. Alteration of As-bearing phases in a small watershed located on a high grade arsenic-geochemical anomaly (French Massif Central)
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Cécile Grosbois, Hubert Bril, Alexandra Courtin-Nomade, Suzanne Beauchemin, Angélique Bossy, W. Hendershot, Groupement de Recherche Eau, Sol, Environnement (GRESE), Université de Limoges (UNILIM), Transferts continentaux : forçages anthropiques, climatiques et géodynamiques, Institut des Sciences de la Terre d'Orléans (ISTO), Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS), Natural Resources Canada (NRCan), McGill University = Université McGill [Montréal, Canada], Conseil régional du Limousin (France), GRESE Laboratory (France), BRGM (France), Natural Resources Canada, (CANMET-MMSL, Canada) and University of McGill (Canada), and Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Université de Tours-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Université de Tours-Centre National de la Recherche Scientifique (CNRS)
- Subjects
geography ,geography.geographical_feature_category ,Bedrock ,[SDE.MCG]Environmental Sciences/Global Changes ,Pharmacosiderite ,Mineralogy ,Sediment ,Weathering ,Electron microprobe ,010501 environmental sciences ,010502 geochemistry & geophysics ,01 natural sciences ,Pollution ,6. Clean water ,Pedogenesis ,13. Climate action ,Geochemistry and Petrology ,[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry ,Soil water ,Environmental Chemistry ,Soil horizon ,Geology ,0105 earth and related environmental sciences - Abstract
At a watershed scale, sediments and soil weathering exerts a control on solid and dissolved transport of trace elements in surface waters and it can be considered as a source of pollution. The studied subwatershed (1.5 km{sup 2}) was located on an As-geochemical anomaly. The studied soil profile showed a significant decrease of As content from 1500 mg kg{sup -1} in the 135-165 cm deepest soil layer to 385 mg kg{sup -1} in the upper 0-5 cm soil layer. Directly in the stream, suspended matter and the
- Published
- 2010
13. Design and Validation of a Mobile Robot for Power Line Inspection and Maintenance
- Author
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Serge Montambault, Nicolas Pouliot, Centre de la Technologie de l'Energie de Canmet - Varennes (CTEC), Ressources Naturelles Canada, and Documentation, Inria Rhône-Alpes
- Subjects
0209 industrial biotechnology ,Computer science ,ACM: I.: Computing Methodologies/I.2: ARTIFICIAL INTELLIGENCE/I.2.9: Robotics ,020209 energy ,[INFO.INFO-RB] Computer Science [cs]/Robotics [cs.RO] ,Mobile robot ,Control engineering ,02 engineering and technology ,Electromagnetic interference ,020901 industrial engineering & automation ,Teleoperated robot ,Obstacle ,0202 electrical engineering, electronic engineering, information engineering ,Key (cryptography) ,[INFO.INFO-RB]Computer Science [cs]/Robotics [cs.RO] ,Line (text file) ,Power line inspection ,Simulation ,Field conditions - Abstract
International audience; This paper presents the LineScout Technology, a mobile teleoperated robot for power line inspection and maintenance. Optimizing several geometric parameters achieved a compact design that was successfully tested over many line configurations and obstacle sequences. An overview of the technology is presented, including a description of the control strategy, followed by a section focusing on key aspects of the prototype thorough validation. Working on live lines, up to 735 kV and 1,000 A, means that the technology must be robust to electromagnetic interference. The third generation prototype, tested in laboratory and in field conditions, is now ready to undertake inspection pilot projects.
- Published
- 2008
14. New cascades for thermo-chemical refrigeration
- Author
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J. Berthiaud, Fernand Rheault, Nathalie Mazet, Mikhail Sorin, Bernard Spinner, Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Centre de la Technologie de l'Energie de Canmet - Varennes (CTEC), and Ressources Naturelles Canada
- Subjects
Exergy ,Computer science ,020209 energy ,Thermodynamics ,02 engineering and technology ,7. Clean energy ,Cascade system ,Operational system ,020401 chemical engineering ,Refrigeration ,Waste heat ,Thermal ,0202 electrical engineering, electronic engineering, information engineering ,PIEnergie ,0204 chemical engineering ,Process engineering ,business.industry ,General Engineering ,Condensed Matter Physics ,Thermochemical process ,Cascade ,Heat transfer ,Key (cryptography) ,business - Abstract
International audience; A diagrammatical approach for the design of new thermo-chemical cascades for heat management purposes is proposed. The two key elements of this approach are: a method to automatically generate system architectures and a general approach to selecting appropriate materials. It is based on establishing an explicit correspondence between the exergy balance around a thermo chemical system, the properties of the reactants and the operational system parameters. A new auto thermal configuration involving two thermally coupled single effect processes is proposed and suitable materials for its implementation are identified. The method is illustrated for the design of an experimental installation for the testing of a thermo-chemical refrigeration system operated at distance from a heat source.
- Published
- 2005
15. Deashing of CANMET coprocessing light oil products. Part 1 : emulsification and liquid-liquid transfer
- Author
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Majid, Abdul, Sparks, Bryan D., Ikura, Michio, and Energy Research Laboratories CANMET, Mines and Resources
- Abstract
This report summarises the results of an investigation of a novel process for ash removal from CANMET coprocessing residues. It is a continuation of contract work originally undertaken by SNC Inc. The exploratory work by SNC indicated that ash contained in coprocessing residues could be effectively removed from the oil by transfer to the acqueous phase during emulsification of the residues in water under proper process conditions. In this investigation we have confirmed the key experimental results reported by SNC and have further developed the process.
- Published
- 1990
16. Deashing of vacuum residue from the CANMET coprocessing unit. Part III : emulsification at high temperature and pressure
- Author
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Sparks, Bryan D., Majid, Abdul, Ikura, Michio, and Energy Research Laboratories, CANMET, Energy, Mines and Resources
- Subjects
technology, industry, and agriculture ,respiratory system ,complex mixtures - Abstract
The operation of the CANMET coal-heavy oil coprocessing unit results in the production of a vacuum residue which contains all the ash from the feed coal as well as the iron compounds formed from the catalyst precursor. Earlier work by the SNC and NRC (1,2) demonstrated that deashing of the lighter oils from the coprocessor was possible. The approach involved the use of chemicals and high intensity mixing to emulsify the oil and promote transfer of the ash forming solids from the oil into the aqueous phase.
- Published
- 1990
17. Deashing of vacuum residue from the CANMET coprocessing unit. Part II : agglomeration and flotation methods
- Author
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Majid, Abdul, Sparks, Bryan D., Ikura, Michio, and Energy Research Laboratories, CANMET, Energy, Mines and Resources
- Abstract
This is the second part of a report summarizing the results of an investigation of deashing vacuum residue from the CANMET coal-oil coprocessing unit. The results of a number of preliminary experiments involving agglomeration and floatation methods are reported. Levels of ash rejection in these experiments was low (15-40 percent) compared with the emulsification/demulsification experiments reported in Part I (64.5 + or - 16 percent). However, it is anticipated that with proper conditioning and process optimization, it will be possible to achieve better results.
- Published
- 1990
18. 'Effect of Water Dispersible Polymers on the Properties of Superplasticized Cement Paste, Mortar, and Concrete'
- Author
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J. J. Beaudoin, V. S. Ramachandran, American Concrete Institute, and CANMET
- Subjects
cement ,plasticizers ,porosity ,Materials science ,mortar setting agents ,mortier ,cement pastes ,materiau polymérique ,ciment ,adjuvant ,Flexural strength ,setting ,Adjuvants ,accéleration de prise ,ethylene copolymers ,Composite material ,Porosity ,polymers ,Shrinkage ,chemistry.chemical_classification ,hardening ,Admixtures ,Plasticizer ,mortars ,pâte (forme) ,résistance à la compression ,Polymer ,compressive strength ,Cement paste ,Mortar ,concrete admixtures ,shrinkage ,Compressive strength ,resins ,chemistry ,flexural strength ,styrene copolymers ,workability ,concrete ,plastics ,paste (state) - Abstract
A study was designed to assess the merits of polymer addition to superplasticized cement paste, mortar and concrete. Three superplasticizers - a sulfonated melamine formaldehyde, a sulfonated naphthalene formaldehyde and a commercial superplasticizer were used in combination with experimental polymers. Polymer and super-plasticizer dosages ranged from 0-15% and 0-0,3% respectively. The effect of binary admixture systems - (superplasticizer and polymer) - on the physico-mechanical properties of the cementitious systems was determined. Properties investigated included the following; slump retention, setting time, compressive strength, flexural strength, surface area, porosity and density. Compatibility of the polymers with the superplasticizer was assessed with respect to the influence of the individual admixtures on the properties of the various systems. Synergistic effects were observed for one polymer, the results of which are discussed in detail., Proc. 3rd Int. Conf on Superplasticizers and Other Chemical Admixtures in Concrete: 1989, Ottawa, Ont. Canada
- Published
- 1989
19. Publisher Correction: Exploiting redundancy in large materials datasets for efficient machine learning with less data.
- Author
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Li K, Persaud D, Choudhary K, DeCost B, Greenwood M, and Hattrick-Simpers J
- Published
- 2024
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20. Exploiting redundancy in large materials datasets for efficient machine learning with less data.
- Author
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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
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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
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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. Thermal Charging Optimization of a Wavy-Shaped Nano-Enhanced Thermal Storage Unit.
- Author
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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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- View/download PDF
24. 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
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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 Cd2+ . 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(H2 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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- View/download PDF
25. A density functional theory investigation of the interaction of the tetraaqua calcium cation with bidentate carbonyl ligands.
- Author
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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(H2 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 NH2 , OCH3 , OH, CH3 , H, F, Cl, CN and NO2 are functional groups with distinct electron-donating and -withdrawing effects that bond directly to the sp2 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(H2 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
- Full Text
- View/download PDF
26. A new method for the characterisation and quantitative speciation of base metal smelter stack particulates.
- Author
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Skeaff JM, Thibault Y, and Hardy DJ
- Subjects
- Air Pollutants chemistry, Atmosphere chemistry, Lead analysis, Lead chemistry, Metallurgy, Metals chemistry, Microscopy, Electron, Scanning, Particle Size, Particulate Matter chemistry, X-Ray Diffraction, Zinc analysis, Zinc chemistry, Air Pollutants analysis, Environmental Monitoring methods, Industrial Waste analysis, Metals analysis, Particulate Matter analysis
- Abstract
Base metal smelters may be a source of particulates containing metals of environmental concern released to the atmosphere. Knowledge of the quantitative chemical speciation of particulate releases from base metal smelters will be of value in smelter emission fingerprinting, site-specific risk assessments, predictions of the behaviour of smelter stack particulates released to the environment and in resolving liability issues related to current and historic releases. Accordingly, we have developed an innovative approach comprising bulk chemical analysis, a leaching procedure, X-ray diffraction analysis and scanning electron microscopy/electron probe microanalysis characterisation in a step-wise apportioning procedure to derive the quantitative speciation of particulate samples from the stacks of three copper smelters designated as A, B and C. For the A smelter stack particulates, the major calculated percentages were 29 CuSO(4), 20 ZnSO(4).H(2)O, 13 (Cu(0.94)Zn(0.06))(2)(AsO(4))(OH), 11 PbSO(4) and four As(2)O(3). For the B smelter stack particulates, the primary calculated percentages were 20 ZnSO(4).H(2)O, 20 PbSO(4), 12 CuSO(4) and nine As(2)O(3). Finally, we calculated that the C smelter stack particulates mostly comprised 34 ZnSO(4).H(2)O, 19 (Cu(0.84)Zn(0.16))(AsO(3)OH), 11 PbSO(4), 10 As(2)O(3) and nine Zn(3)(AsO(4))(2). Between 56% and 67% by weight of the smelter stack particulates, including the As, was soluble in water. For these and other operations, the data and approach may be useful in estimating metals partitioning among water, soil and sediment, as well as predictions of the effects of the stack particulates released to the environment.
- Published
- 2011
- Full Text
- View/download PDF
27. Development and validation of a chronic copper biotic ligand model for Ceriodaphnia dubia.
- Author
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Schwartz ML and Vigneault B
- Subjects
- Animals, Biodiversity, Calcium chemistry, Canada, Cations, Cladocera physiology, Copper pharmacokinetics, Hydrogen-Ion Concentration, Ligands, Magnesium chemistry, Models, Biological, Organic Chemicals chemistry, Reproducibility of Results, Sodium chemistry, Toxicity Tests, Water Pollutants, Chemical pharmacokinetics, Cladocera drug effects, Copper toxicity, Water Pollutants, Chemical toxicity
- Abstract
A biotic ligand model (BLM) to predict chronic Cu toxicity to Ceriodaphnia dubia was developed and tested. The effect of cationic competition, pH and natural organic matter complexation of Cu was examined to develop the model. There was no effect of cationic competition using increasing Ca and Na concentrations in our exposures. However, we did see a significant regression of decreasing toxicity (measured as the IC25; concentration at which there was a 25% inhibition of reproduction) as Mg concentration increased. However, taking into account the actual variability of the IC25 and since the relative increase in IC25 due to additional Mg was small (1.5-fold) Mg competition was not included in the model. Changes in pH had a significant effect on Cu IC25, which is consistent with proton competition as often suggested for acute BLMs. Finally, natural organic matter (NOM) was added to exposures resulting in significant decreases in toxicity. Therefore, our predictive model for chronic Cu toxicity to C. dubia includes the effect of pH and NOM complexation. The model was validated with Cu IC25 data generated in six natural surface waters collected from across Canada. Using WHAM VI, we calculated Cu speciation in each natural water and using our model, we generated "predicted" IC25 data. We successfully predicted all Cu IC25 within a factor of 3 for the six waters used for validation.
- Published
- 2007
- Full Text
- View/download PDF
28. A pilot-plant study for destruction of PCBs in contaminated soils using fluidized bed combustion technology.
- Author
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Desai DL, Anthony EJ, and Wang J
- Subjects
- Pilot Projects, Environmental Restoration and Remediation methods, Incineration methods, Polychlorinated Biphenyls chemistry, Soil Pollutants chemistry
- Abstract
Destruction of polychlorinated biphenyls (PCBs) in contaminated soils and wastes using circulating fluidized bed combustion (CFBC) technology was studied using a pilot plant and simulated waste material. The results show that the technology is effective and particularly promising for treatment of PCB-containing materials like the toxic sludge from a large contaminated site. Destruction of the toxics in the gas phase appears to be very fast, and over 99.9999% destruction and removal efficiency can be achieved in the temperature range 875-880 degrees C. Heat transfer in the fluidized bed also appears adequate. Toxic residues in treated soil can be reduced to very low levels. Rate-controlling factors of the decontamination process are analyzed, and key issues for determination of the process conditions are discussed.
- Published
- 2007
- Full Text
- View/download PDF
29. Optimization of culture conditions and properties of immobilized sulfide oxidase from Arthrobacter species.
- Author
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Mohapatra BR, Gould WD, Dinardo O, Papavinasam S, and Revie RW
- Subjects
- Enzyme Activation, Enzyme Stability, Enzymes, Immobilized, Oxidoreductases Acting on Sulfur Group Donors analysis, Quality Control, Arthrobacter growth & development, Arthrobacter metabolism, Bioreactors microbiology, Cell Culture Techniques methods, Oxidoreductases Acting on Sulfur Group Donors biosynthesis, Oxidoreductases Acting on Sulfur Group Donors chemistry
- Abstract
Arthrobacter species strain FR-3, isolated from sediments of a swamp, produced a novel serine-type sulfide oxidase. The production of sulfide oxidase was maximal at pH 7.5 and 30 degrees C. Among various carbon and nitrogen sources tested, glucose and yeast extract were found to be the most effective substrates for the secretion of sulfide oxidase. The sulfide oxidase was purified to homogeneity and the molecular weight of the purified enzyme was 43 kDa when estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified sulfide oxidase can be effectively immobilized in DEAE (diethylaminoethyl)-cellulose matrix with a yield of 66%. The purified free and immobilized enzyme had optimum activity at pH 7.5 and 6.0, respectively. Immobilization increases the stability of the enzyme with respect to temperature. The half-life of the immobilized enzyme was 30 min at 45 degrees C, longer than that of the free enzyme (10 min). The purified free sulfide oxidase activity was completely inhibited by 1 mM Co2+ and Zn2+ and sulfhydryl group reagents (para-chloromercuribenzoic acid and iodoacetic acid). Catalytic activity was not affected by 1 mM Ca2+, Mg2+, Na+ and metal-chelating agent (EDTA).
- Published
- 2006
- Full Text
- View/download PDF
30. TEM investigation of nanophase aluminum powder.
- Author
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Gertsman VY and Kwok QS
- Abstract
Nanophase aluminum powder was characterized in a field-emission-gun transmission electron microscope (TEM). Different techniques were used to investigate the structure of the particles, including conventional bright-field and dark-field imaging, scanning transmission electron microscopy (STEM), high-resolution lattice imaging, diffraction studies, energy dispersive X-ray spectroscopy (EDS) analysis and mapping, and electron energy loss spectroscopy (EELS) analysis and mapping. It has been established that the particle cores consist of aluminum single crystals that sometimes contain crystal lattice defects. The core is covered by a passivating layer of aluminum oxide a few nanometers thick. The alumina is mostly amorphous, but evidences of partial crystallinity of the oxide were also found. The thickness of this layer was measured using different techniques, and the results are in good agreement with each other. The particles are agglomerated in two distinct ways. Some particles were apparently bonded together during processing before oxidation. These mostly form dumbbells covered by a joint oxide layer. Also, oxidized particles are loosely assembled into relatively large clusters.
- Published
- 2005
- Full Text
- View/download PDF
31. Dioxins/furans emissions from fluidized bed combustion of salt-laden hog fuel.
- Author
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Preto F, McCleave R, McLaughlin D, and Wang J
- Subjects
- Carbon chemistry, Coal Ash, Dibenzofurans, Polychlorinated, Environmental Monitoring, Gases, Industrial Waste, Paper, Particulate Matter, Temperature, Benzofurans analysis, Incineration, Polychlorinated Dibenzodioxins analogs & derivatives, Polychlorinated Dibenzodioxins analysis
- Abstract
Polychlorinated dibenzodioxins/furans (PCDD/F) were formed in substantial quantities in a pilot-scale fluidized bed combustor burning salt-laden waste wood, a common fuel for Canadian coastal pulp and paper mills. Formation of PCDD/F increased with increasing chloride content in the feed, and appeared to correlate with the chlorine content in the fly ash. It took a very long time for the ash chlorine content to stabilize, suggesting that chlorine transferred slowly from the flue gas to the ash. The baghouse may contribute largely to formation of the PCDD/F, owing to its temperature range and the potentially long residence time for ash particles. Controlling the baghouse temperature to reduce the PCDD/F formation in the baghouse should be effective in reducing the total emission level. While sulphur addition was found to reduce the emission level by as much as 90%, the emission level was still above the regulated level for the mills burning salt-laden wood under the conditions of the present study. No relation between the emission level and CO concentration in the flue gas was observed.
- Published
- 2005
- Full Text
- View/download PDF
32. Industrial-scale demonstration of a new sorbent reactivation technology for fluidized bed combustors.
- Author
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Anthony EJ, McCleave R, Gandolfi E, and Wang J
- Subjects
- Adsorption, Carbon Dioxide analysis, Coal, Construction Materials, Costs and Cost Analysis, Incineration, Refuse Disposal economics, Industrial Waste, Refuse Disposal methods
- Abstract
To minimize the disposal of highly reactive spent sorbent from a fluidized bed combustor, a new method for reactivation has been developed. The method consists of grinding the spent ash in a rotary mill, hydrating the ash with an excess of water, and mixing the wet ground ash with dry solids to absorb the excess water. The mixing process eliminates the formation of a concrete-like product that normally results as wet fluidized bed combustor ash ages. Pilot-scale combustion trials proved to be successful, and the process was scaled up using a 35MWt utility boiler at Purdue University. The test lasted for 3 days and resulted in net reduction of limestone sorbent use of 18%. The results generated in this work have been used to develop an economic evaluation for a 165MWe circulating fluidized bed (CFB) boiler, which projects significant savings due to reduction of limestone supply and ash disposal costs. The evaluation also suggests that the process is cost competitive with other processes, albeit that those processes have not been demonstrated at industrial scale. Furthermore, it also has the potential to make a small net reduction in CO(2) emissions, due to reduced limestone usage.
- Published
- 2003
- Full Text
- View/download PDF
33. Emulsification through Area Contraction.
- Author
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Dabros T, Yeung A, Masliyah J, and Czarnecki J
- Abstract
Emulsification requiring very little input energy can be induced at an oil-water interface that is initially in a state of equilibrium. The process involves destabilization, through contraction, of local interfacial regions. For emulsification to occur, it is necessary for the interfacial structure to have no resistance to surface shearing. Such a mechanism of emulsification may have important implications for the approach to solving emulsion problems in the petroleum industry. Copyright 1999 Academic Press.
- Published
- 1999
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34. Infrared Study of the Intercalation of Kaolinite by Caesium Bromide and Caesium Iodide.
- Author
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Michaelian KH, Lapides I I, Lahav N, Yariv S, and Brodsky I I
- Abstract
CsBr- and CsI-kaolinite intercalation complexes were synthesized by gradually heating caesium halide disks of the DMSO-kaolinite intermediate up to 330 degreesC. Infrared spectroscopy revealed two types of complexes with the caesium salts: almost nonhydrous, obtained during thermal treatment of the DMSO complex, and hydrated, produced by regrinding the disk in air. Comparison of band positions for CsBr-kaolinite and CsI-kaolinite with those for the CsCl complex (observed in a previous study) shows that the strength of the hydrogen bond between the intercalated halide and the inner surface hydroxyl decreases on the order CsCl > CsBr > CsI. The nonreactivity of CsI in mechanochemical intercalation may arise from weak interaction between I- and inner surface hydroxyl groups, resulting from the fact that caesium is a very soft acid and iodide is a very soft base. Consequently, the very strong interaction between the two ions in the crystal is not disrupted during mechanochemical treatment. Copyright 1998 Academic Press and Minister of Natural Resources, Canada.
- Published
- 1998
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35. Reduction of Selenate and Selenite to Elemental Selenium by a Pseudomonas stutzeri Isolate.
- Author
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Lortie L, Gould WD, Rajan S, McCready RG, and Cheng KJ
- Abstract
A Pseudomonas stutzeri isolate rapidly reduced both selenite and selenate ions to elemental selenium at initial concentrations of both anions of up to 48.1 mM. Optimal selenium reduction occurred under aerobic conditions between pH 7.0 and 9.0 and at temperatures of 25 to 35 degrees C. Reduction of both selenite and selenate was unaffected by a number of anions except for sulfite, chromate, and tungstate ions, which inhibited both growth and reduction.
- Published
- 1992
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36. Rhizobacteria of cotton and their repression of seedling disease pathogens.
- Author
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Hagedorn C, Gould WD, and Bardinelli TR
- Abstract
During the 1983 field season, the rhizobacteria (including organisms from rhizosphere soil and the root rhizoplane) of cotton plants at one location in Mississippi were inventoried at different plant growth stages. Isolates (1,000) were identified to the genus level and characterized for repression of Pythium ultimum and Rhizoctonia solani. Cotton seedlings were initially colonized by bacteria of many different genera, and populations quickly reached 10 CFU/g of root tissue. As the season progressed, the bacterial populations declined as root mass increased and the roots became more woodlike in consistency. Fluorescent pseudomonads were the most numerous gram-negative rhizobacterial isolates of those that were randomly collected and identified, and they provided the largest number of isolates with fungal repressive activity. Several other gram-negative bacterial genera were recovered throughout the growing season, and some gram-positive bacteria were also isolated routinely, but at lower numbers. There was no correlation between the proportion of rhizobacterial isolates that possessed fungal repressive activity and the plant growth stage from which the isolates were obtained. Approximately twice as many bacterial isolates demonstrated fungal repression in the agar assay compared with the inplanta assay, and isolates were found more frequently with fungal repressive activity against P. ultimum than against R. solai.
- Published
- 1989
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37. Radon (thoron) daughter measurements with an automated, programmable, radiation monitor.
- Author
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Bigu J and Vandrish G
- Abstract
A technical evaluation of an automated, programmable, grab-sampler manufactured by Pylon Electronic Development under the commercial name WL-1000C has been conducted. Six different methods are implemented in the instrument for analyzing radiation data. Any one method can be used on command and easily selected by means of a keyboard. Available radiation data that can be retrieved on command include radon (thoron) daughter concentrations and radon (thoron) Working Levels. Measurements were carried out under laboratory-controlled conditions in a large (26 m(3)) radon/thoron test facility, designed for calibration purposes, and at an underground uranium mine. Data obtained with the WL-1000C have been compared with conventional grab-sampling (e.g., Kusnetz, Thomas-Tsivoglou and Markov methods) and with other automated radiation instrumentation previously tested at our laboratories. Tests were done under constant radiation conditions and also under rapidly fluctuating conditions in order to determine the response of the instruments and methods in these two cases of practial interest. The Working Level used in these experiments was in the approximate range of 0.01 to 10 WL. Tests were conducted under a variety of environmental conditions. Good agreement with grab-sampling data was found for radon daughters. Some discrepancies with grab-sampling data were found for radon daughter/thoron daughter mixtures. Disagreement in the latter case is to be expected because of α-energy overlap between RaA and ThC.
- Published
- 1986
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