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51. Crime sexual e esquizofrenia: aspectos forenses: relato de caso

Author

Alexandre Martins Valença, Lisieux Elaine de Borba Telles, Jose Brasileiro Dourado Junior, Leonardo Fernandez Meyer, Luiz Felipe Rigonatti, Talvane Marins de Moraes, Antônio Geraldo da Silva, and Antonio Egidio Nardi

Subjects
esquizofrenia, psicose, crime sexual, ofensa sexual, imputabilidade, Psychiatry, RC435-571
Abstract

É apresentado o caso de um indivíduo com diagnóstico de esquizofrenia que cometeu um delito sexual e foi submetido a perícia psiquiátrica para avaliação de responsabilidade penal, sendo considerado inimputável. São discutidos fatores que podem contribuir para delitos dessa natureza, em indivíduos com transtornos psicóticos. Parecer CEP: Instituto de Psiquiatria da Universidade Federal do Rio de Janeiro, IPUB - Número do Parecer: 1.334.993

Published
2024
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52. Numerical Simulation of an Arc Jet Test Section

Author

Umran Duzel, Huaibao Zhang, Olivia Schroeder, and Alexandre Martin

Subjects
Fluid Flow and Transfer Processes, Jet (fluid), Hypersonic speed, Computer simulation, Mechanical Engineering, Aerospace Engineering, ComputerApplications_COMPUTERSINOTHERSYSTEMS, 02 engineering and technology, Mechanics, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, Arc (geometry), 020303 mechanical engineering & transports, 0203 mechanical engineering, Space and Planetary Science, Section (archaeology), 0103 physical sciences, Geology, Test data
Abstract

High-fidelity modeling tools are essential for accurate predictions of planetary entry. The same tools can also be used to interpret ground test data. A hypersonic aerothermodynamic computational f...

Published
2020
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53. A combination theorem for combinatorially non-positively curved complexes of hyperbolic groups

Author

Damian Osajda and Alexandre Martin

Subjects
Pure mathematics, Gromov boundary, General Mathematics, 010102 general mathematics, Boundary (topology), Curvature, 01 natural sciences, Action (physics), 0103 physical sciences, Graph (abstract data type), Order (group theory), 010307 mathematical physics, 0101 mathematics, Mathematics
Abstract

We prove a combination theorem for hyperbolic groups, in the case of groups acting on complexes displaying combinatorial features reminiscent of non-positive curvature. Such complexes include for instance weakly systolic complexes and C'(1/6) small cancellation polygonal complexes. Our proof involves constructing a potential Gromov boundary for the resulting groups and analyzing the dynamics of the action on the boundary in order to use Bowditch’s characterisation of hyperbolicity. A key ingredient is the introduction of a combinatorial property that implies a weak form of non-positive curvature, and which holds for large classes of complexes.As an application, we study the hyperbolicity of groups obtained by small cancellation over a graph of hyperbolic groups.

Published
2020
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69. Thermal Expansion for Charring Ablative Materials

Author

Alexandre Martin, Rui Fu, Jonathan F. Wenk, and Haoyue Weng

Subjects
Fluid Flow and Transfer Processes, Materials science, Mechanical Engineering, Aerospace Engineering, 02 engineering and technology, Deformation (meteorology), Solver, Condensed Matter Physics, 01 natural sciences, GeneralLiterature_MISCELLANEOUS, Thermal expansion, 010305 fluids & plasmas, 020303 mechanical engineering & transports, 0203 mechanical engineering, Space and Planetary Science, Space Shuttle thermal protection system, 0103 physical sciences, Ablative case, Charring, Composite material, Material properties, Pyrolysis, ComputingMethodologies_COMPUTERGRAPHICS
Abstract

A mesh moving scheme is developed and tested in a finite-volume thermo-mechanical solver to investigate the effects of geometry deformation on thermal protection system materials. Verification case...

Published
2020
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70. Automorphisms of graph products of groups from a geometric perspective

Author

Anthony Genevois and Alexandre Martin

Subjects
Vertex (graph theory), Cayley graph, General Mathematics, 010102 general mathematics, Discrete geometry, Metric Geometry (math.MG), Group Theory (math.GR), Automorphism, 01 natural sciences, Graph, Combinatorics, Mathematics::Group Theory, Conjugacy class, Mathematics - Metric Geometry, 0103 physical sciences, Homogeneous space, FOS: Mathematics, 010307 mathematical physics, 20E36, 20F65, 20E06, 0101 mathematics, Mathematics - Group Theory, Graph product, Mathematics
Abstract

This article studies automorphism groups of graph products of arbitrary groups. We completely characterise automorphisms that preserve the set of conjugacy classes of vertex groups as those automorphisms that can be decomposed as a product of certain elementary automorphisms (inner automorphisms, partial conjugations, automorphisms associated to symmetries of the underlying graph). This allows us to completely compute the automorphism group of certain graph products, for instance in the case where the underlying graph is finite, connected, leafless and of girth at least $5$. If in addition the underlying graph does not contain separating stars, we can understand the geometry of the automorphism groups of such graph products of groups further: we show that such automorphism groups do not satisfy Kazhdan's property (T) and are acylindrically hyperbolic. Applications to automorphism groups of graph products of finite groups are also included. The approach in this article is geometric and relies on the action of graph products of groups on certain complexes with a particularly rich combinatorial geometry. The first such complex is a particular Cayley graph of the graph product that has a quasi-median geometry, a combinatorial geometry reminiscent of (but more general than) CAT(0) cube complexes. The second (strongly related) complex used is the Davis complex of the graph product, a CAT(0) cube complex that also has a structure of right-angled building., Comment: 36 pages. The article subsumes and vastly generalises our preprint arXiv:1803.07536. To appear in Proc. Lond. Math. Soc

Published
2019
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71. Calibration and Uncertainty Quantification of VISTA Ablator Material Database Using Bayesian Inference

Author

Ali D. Omidy, Marco Panesi, Haoyue Weng, Alexandre Martin, Przemyslaw Rostkowski, and Simone Venturi

Subjects
Fluid Flow and Transfer Processes, Calibration (statistics), Computer science, Mechanical Engineering, AVCOAT, Crew, Aerospace Engineering, Experimental data, 02 engineering and technology, Inverse problem, Condensed Matter Physics, Bayesian inference, computer.software_genre, 01 natural sciences, 010305 fluids & plasmas, 020303 mechanical engineering & transports, 0203 mechanical engineering, Space and Planetary Science, Space Shuttle thermal protection system, 0103 physical sciences, Data mining, Uncertainty quantification, computer
Abstract

The current design of NASA’s Multi-Purpose Crew vehicle uses the latest iteration of AVCOAT, an ablating thermal protection material. However, restrictions placed on the export of experimental data...

Published
2019
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78. Evaluation of the Anisotropic Radiative Conductivity of a Low-Density Carbon Fiber Material from Realistic Microscale Imaging

Author

Nima Nouri, Francesco Panerai, Kaveh A Tagavi, Nagi N Mansour, and Alexandre Martin

Subjects
Composite Materials, Fluid Mechanics And Thermodynamics
Abstract

The radiative heat transfer inside a low-density carbon fiber insulator is analyzed using a three-dimensional direct simulation model. A robust procedure is presented for the numerical calculation of the geometric configuration factor to compute the radiative energy exchange processes among the small discretized surface areas of the fibrous material. The methodology is applied to a polygonal mesh of a fibrous insulator obtained from three-dimensional microscale imaging of the real material. The anisotropic values of the radiative conductivity are calculated for that geometry. The results yield both directional and thermal dependence of the radiative conductivity.

Published
2015
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79. Combined physical training protects the left ventricle from structural and functional damages in experimental pulmonary arterial hypertension

Author

Luciano Bernardes Leite, Leôncio Lopes Soares, Alexandre Martins Oliveira Portes, Thayana Inácia Soares, Bruna Aparecida Fonseca da Silva, Taís Rodrigues Dias, Sebastião Felipe Ferreira Costa, Luiz Otávio Guimarães-Ervilha, Mirian Quintão Assis, Victor Neiva Lavorato, Albená Nunes da Silva, Mariana Machado-Neves, Emily Correna Carlo Reis, and Antônio José Natali

Subjects
Pulmonary arterial hypertension, Physical training, LV myocyte contractility, Adverse remodeling, Oxidative stress, Medicine, Internal medicine, RC31-1245
Abstract

Abstract Background Under the adverse remodeling of the right ventricle and interventricular septum in pulmonary arterial hypertension (PAH) the left ventricle (LV) dynamics is impaired. Despite the benefits of combined aerobic and resistance physical trainings to individuals with PAH, its impact on the LV is not fully understood. Objective To test whether moderate-intensity combined physical training performed during the development of PAH induced by MCT in rats is beneficial to the LV’s structure and function. Methods Male Wistar rats were divided into two groups: Sedentary Hypertensive Survival (SHS, n = 7); and Exercise Hypertensive Survival (EHS, n = 7) to test survival. To investigate the effects of combined physical training, another group of rats were divided into three groups: Sedentary Control (SC, n = 7); Sedentary Hypertensive (SH, n = 7); and Exercise Hypertensive (EH, n = 7). PAH was induced through an intraperitoneal injection of MCT (60 mg/kg). Echocardiographic evaluations were conducted on the 22nd day after MCT administration. Animals in the EHS and EH groups participated in a combined physical training program, alternating aerobic (treadmill running: 50 min, 60% maximum running speed) and resistance (ladder climbing: 15 climbs with 1 min interval, 60% maximum carrying load) exercises, one session/day, 5 days/week for approximately 4 weeks. Results The physical training increased survival and tolerance to aerobic (i.e., maximum running speed) and resistance (i.e., maximum carrying load) exertions and prevented reductions in ejection fraction and fractional shortening. In addition, the physical training mitigated oxidative stress (i.e., CAT, SOD and MDA) and inhibited adverse LV remodeling (i.e., Collagen, extracellular matrix, and cell dimensions). Moreover, the physical training preserved the amplitude and velocity of contraction and hindered the reductions in the amplitude and velocity of the intracellular Ca2+ transient in LV single myocytes. Conclusion Moderate-intensity combined physical training performed during the development of MCT-induced PAH in rats protects their LV from damages to its structure and function and hence increases their tolerance to physical exertion and prolongs their survival.

Published
2024
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88. Experimental and Numerical Investigation of Steady Fluid Forces in Axial Flow on a Cylinder Confined in a Cylinder Array

Author

Nicolas de Buretel de Chassey, Luc Pastur, Pierre Moussou, Olivier Cadot, Alexandre Martin, Aurélien Joly, and Pierre Badel

Subjects
Physics, Reynolds number, Mechanics, Curvature, Cylinder (engine), law.invention, Physics::Fluid Dynamics, symbols.namesake, Acceleration, Axial compressor, law, Fluid–structure interaction, symbols, Central cylinder, Wind tunnel
Abstract

The goal of the paper is to investigate experimentally and numerically the Taylor-Lighthill-Paidoussis (TLP) model of fluid forces in axial flow, in the case of a flexible cylinder confined in a cylinder array. This model assumes that the local fluid forces depend only on the local angle, curvature, velocity and acceleration of the structure. The experimental setup consists of a wind tunnel with a test section of length 2m and of width 24cm, surrounding a square array of 3x3 cylinders with pitch-to-diameter ratio 1.33. The Reynolds number is about 100000. The central cylinder can be statically rotated or translated. The steady resultant fluid forces exerted on it are recorded using a 6-axis load cell. Experimental and numerical results are in good agreement. The TLP model performs well at predicting some of the forces measured. However, further investigation on the space distribution of these forces is needed to fully assess the performance of that model.

Published
2021
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89. Low incidence of SARS-CoV-2, risk factors of mortality and the course of illness in the French national cohort of dialysis patients

Author

Cécile Couchoud, Florian Bayer, Carole Ayav, Clémence Béchade, Philippe Brunet, François Chantrel, Luc Frimat, Roula Galland, Maryvonne Hourmant, Emmanuelle Laurain, Thierry Lobbedez, Lucile Mercadal, Olivier Moranne, Abdelhamid Abbassi, Alain Debure, Abdallah Guerraoui, Abdelatif Benmoussa, Abdelaziz Hamani, Abdelaziz Ziane, Abdelhamid Nefti, Abdelkader Hadj, Abderrahim El Amari, Abderrahmane Ghazali, Abo Bakr Abd El Fatah Mohamed, Achour Laradi, Adel Ben Ahmed, Adel Sahar, Adele Pillet, Adeline Lacraz, Adnan Moinat, Afshin Massoumi, Agathe Pardon, Agnes Caillette Beaudoin, Agnes Chapelet Debout, Agnes Mariot, Ahmed Rachi, Aida Afiani, Aime Remy Boula, Al Jalaby, Alain Cremault, Alain Fournier, Alain Jeanson, Alain Lyon, Alain Nony, Alain Robert, Alain Slingeneyer, Alanor Agnes Labatide, Albane Brodin Sartorius, Albert Bensman, Albert Fournier, Alex Ranlin, Alex Vido Sandor, Alexandra Colombo, Alexandra Duhem, Alexandra Stancu, Alexandre Dufay, Alexandre Dumoulin, Alexandre Ebel, Alexandre Klein, Alexandre Martin, Alexandre Mouneimne, Alexandre Seidowsky, Alfio De Martin, Alfredo Zannier, Ali Aizel, Ali Hafi, Ali Zineddine Diddaoui, Alim Heyani, Alina Mocanu, Alina Preda, Aline Hafi, Aline Talaszka, Alyette Duquesne, Amar Amaouche, Amel Ghemmour, Amelie Simon, Amina Skalli, Amine Boukadida, Amr Ekhlas Ragab Eid, Ana Fedorca, Anabelle Baillet, Anais Poyet, Ancuta Bouffandeau Giorgita, Anderson Ratsimbazafy, Andre Pruna, Angel Argiles, Angelo Testa, Ann Karolien Vandooren, Anne Jolivot, Anne Kolko Labadens, Anne Lataste, Anne Maisin, Anne Paris, Anne Sechet, Anne Wuillai, Anne Elisabeth Heng, Anne Gaelle Josse, Anne Helene Querard, Anne Helene Reboux, Anne Laure Adra, Anne Laure Faller, Anne Laure Leclerc, Anne Laure Poitou, Annie Lahoche Manucci, Antoine Jacquet, Antoine Pommereau, Antoine Thierry, Arezki Adem, Arielle Chapelet, Arnaud Del Bello, Arnaud Delezire, Arnaud Garnier, Arnaud Guerard, Arnaud Klisnick, Arnaud Lionet, Arnaud Roccabianca, Arnaud Stolz, Arthur Capdeville, Asma Allal, Assem Alrifai, Assetou Diarrassouba, Assia Djema, Assia Ferhat Carre, Astrid Godron Dubrasquet, Atman Haddj Elmrabet, Audrey Jegado, Aurelia Bertholet Thomas, Aurelie Davourie Salandre, Aurelie Pajot, Aurelien Lorthioir, Aurelien Tiple, Aurore Sury, Ayman Abokasem, Ayman Sarraj, Bachir Henaoui, Baher Chaghouri, Bassem Wehbe, Beatrice Ball, Beatrice Viron, Belkassem Issad, Benedicte Hodemon Corne, Benedicte Janbon, Benjamin Deroure, Benjamin Savenkoff, Benoit Jonon, Benoit Vendrely, Benyakoub Djelaleddine, Bernard Ohry, Bernard Painchart, Bernard Strullu, Bernard Temperville, Bertin Ebikili, Bertrand Hacq, Bertrand Morel, Bilal Aoun, Blanca Muniz, Bouchra Chlih, Brahim Amara, Brice Mayor, Brigitte Gilson, Brigitte Llanas, Brigitte Zins, Bruno Bourgeon, Bruno Coevoet, Bruno Guery, Bruno Legallicier, Bruno Paris, Bruno Ranchin, Bruno Seigneuric, Camelia Ghiciuc Dita, Camelia Prelipcean, Carine Achard Hottelart, Carine Diet, Carlos Frangie, Carlos Vela, Carmina Muresan, Carole Deprele, Caroline Araujo, Caroline Bidault, Caroline Creput, Caroline Delclaux, Caroline Du Halgouet, Caroline Favennec, Caroline Freguin, Caroline Gourraud Vercel, Caroline Mesguen, Caroline Ndomo Obama, Caroline Poitou, Caroline Preissig Dirhold, Caroline Roubiou, Catherine Albert, Catherine Bessin, Catherine De Marion Gaja, Catherine Godart, Catherine Lasseur, Catherine Leocardi, Catherine Lumbroso, Catherine Melander, Catherine Michel, Catherine Quere Maurouard, Catherine Rouannet, Catherine Taddei, Cathy Verove, Cecile Guiraud, Cecile Tafelin, Cecile Turc Baron, Cedric Formet, Cedric Pinier, Celia Lessore De Ste Foy, Celine Granolleras, Chaouki Bennini, Charles Cartou, Charles Chazot, Charlotte Jouzel, Cherif Badid, Christa Roubicek, Christel Viaud, Christelle Verrier, Christian Chuet, Christian Combe, Christian Dabot, Christian Duvic, Christian Emond, Christian Lagarde, Christian Lamotte, Christian Pain, Christiane Mousson, Christie Lorriaux, Christine Beauchamp, Christine Fumeron, Christine Le Gurun, Christine Leroy, Christine Pietrement, Christine Richer, Christophe Bouaka, Christophe Charasse, Christophe Goupy, Christophe Ridel, Cindy Castrale, Cindy Detourne, Clair Francois, Claire Presne, Claire Trivin, Clarissa Von Kotze, Claude Bernard, Claude Bonniol, Claude Desvergnes, Claude Raharivelina, Claudia Nistor, Claudine Gueret, Claudine Lloret, Claudine Saltiel, Clelia Rosati, Clementine Rabate, Corina Stanescu, Corinne Ferrandini, Corinne Guibergia, Corinne Lemoine, Corinne Passeron, Cynthia Kahil, Cyril Garrouste, Cyril Vo Van, Cyrille Jolimoy, Dalila Kesraoui, Damien Jolly, Damien Thibaudin, Dan Teboulle, Daniel Daubresse, Daniel Louvet, Daniel Rasamimanantsoa, Daniel Toledano, Daniela Babici, Daniela David, Daniela Dincu, Danielle Bruno, Delia May, Delphine Haussaire, Delphine Henriet Viprey, Denis Bugnon, Denis Fouque, Denis Morin, Derradji Nour, Diab Mohamed Mahmoud, Diana Istrati Cristescu, Didier Aguilera, Didier Coste, Didier Hamel, Didier Le Chapois, Didier Testou, Dilaver Erbilgin, Djamal Dahmane, Doan Bui Quang, Dominique Bertrand, Dominique Besnier, Dominique Blanchier, Dominique Briffa, Dominique Caux, Dominique Durand, Dominique Fleury, Dominique Guerrot, Dominique Hestin, Dominique Jaubert, Dominique Joly, Dominique Lombart, Dominique Pagniez, Dominique Pierre, Dominique Schohn, Donatien Ikonga, Dorina Visanica, Dorothee Bazin, Edouard Boury, Edouard Maksour, Ekoue Agbonon, Elarbi Harrami, Elena Marcu, Elena Tudorache, Elisabeth Caniot, Elisabeth Semjen, Elisabeth Tomkiewicz, Elise Scheidt, Elke Gaboriau, Elodie Lamouroux, Elsa Guiard, Elsa Martin Passos, Emerson Nsembani, Emilie Fache, Emilie Kalbacher, Emilie Pambrun, Emilie Pincon, Emma Allain Launay, Emmanuel Baron, Emmanuel Dupuis, Emmanuel Villar, Emmanuelle Charlin, Emmanuelle Hecquet, Emmanuelle Kohler, Emmanuelle Rosier, Enrique Figueroa, Eric Azoulay, Eric Canivet, Eric Daugas, Eric Gauthier, Eric Laruelle, Eric Le Guen, Eric Legrand, Eric Moumas, Eric Postec, Eric Prinz, Eric Renaudineau, Estelle Desport, Estelle Ricard Sutra, Etienne Berard, Etienne Ged, Etienne Robin, Eve Vilaine, Evelyne Bargas, Evelyne Mac Namara, François Combarnous, Fatima Yazbeck, Fabien Gerard, Fabien Metivier, Fabien Parazols, Fabien Soulis, Fabrice Garnier, Fadhila Pech Messaoudene, Fadi Haidar, Fanny Boullenger, Fanny Lepeytre, Fanny Leroy, Fares Frejate, Farid Bellahsene, Farid Bellhasene, Farid Saidani, Fatouma Toure, Faycal Kriaa, Fazia Nemmar, Fernando Vetromile, Florence Chalmin, Florence Lucats, Florence Sens, Florence Villemain, Florent Plasse, Fouad Lebhour, Francis Schillinger, Franck Berge, Franck Bourdon, Franck Bridoux, Franck Reynaud, Francois Babinet, Francois Basse, Francois Chantrel, Francois Clair, Francois Coulomb, Francois De Cornelissen, Francois Glowacki, Francois Marchal, Francois Maurice, Francois Nobili, Francois Pourreau, Francois Provot, Francois Roux Amani, Francoise Broux, Francoise Bulte, Francoise Heibel, Francoise Leonetti, Francoise Moussion Schott, Frank Le Roy, Frederic Besson, Frederic Lavainne, Frederic Tollis, Frederique Bocquentin, Frederique Meeus, Frederique Vecina, Friederike Von Ey, Gabriel Balit, Gabriel Choukroun, Gabriel Gruget, Gabriel Huchard, Gabriella Golea, Gabrielle Duneau, Gaelle Lefrancois, Gaelle Pelle, Gaetan Lebrun, Genevieve Dumont, Georges Brillet, Georges Deschenes, Georges Mourad, Georges Stamatakis, Geraldine Cazajous, Geraldine D'ythurbide, Geraldine Robitaille Wiart, Gerard Cardon, Gerard Champion, Gerard Deschodt, Gerard Mangenot, Gerard Motte, Gerard Schortgen, Ghada Boulahia, Ghassan Maakaroun, Ghylene Bourdat Michel, Gilbert Zanetta, Gilles Hufnagel, Gilles Messier, Giorgina Piccoli, Gregoire Couvrat Desvergnes, Guillaume Bobrie, Guillaume Bonnard, Guillaume Clement, Guillaume Jean, Guillaume Queffeulou, Guillaume Seret, Guillaume Vernin, Guy Delavaud, Guy Lambrey, Guy Rostoker, Gwenaelle Poussard, Gwenaelle Roussey Kesler, H. Leon, Habib Aboubekr, Hacene Boulechfar, Hacene Sekhri, Hadia Hebibi, Hadjira Benalia, Hafed Fessi, Hafsabhai Atchia, Haiat Bittar, Hakim Maiza, Hakim Mazouz, Hamid El Ali, Hammouche Bougrida, Hans Van Der Pijl, Hassan Lokmane, Hassane Izzedine, Hassen Adda, Helene De Preneuf, Helene Leray, Helene Philippot, Henri Boulanger, Henri Merault, Henri Renaud, Herve Bonarek, Herve Maheut, Hilaire Nzeyimana, Hocine Mehama, Hocine Zaidi, Hugo Weclawiak, Hugues Flodrops, Huseyin Karaaslan, Ibrahim Haskour, Ihssen Belhadj, Imad Almoubarak, Imad Haddad, Ines Castellano, Ines Ferrandiz, Ioana Daniliuc, Ioana Darie, Ioana Enache, Ionut Prunescu, Irenee Djiconkpode, Irina Shahapuni, Isabelle Bouchoule, Isabelle Devriendt, Isabelle Kazes, Isabelle Kolb, Isabelle Landru, Isabelle Poli, Isabelle Rey, Isabelle Segalen, Isabelle Selcer, Isabelle Vernier, Isabelle Vrillon, Ismahane Guenifi, J. Dominique Gheerbrandt, Jacky Potier, Jacques Becart, Jacques Cledes, Jacques Ducros, Jacques Duvic, Jacques Fourcade, Jacques Gaultier, Jacques Jurine, Jacques Lebleu, Jacques Ollier, Jacques Ibsen Charles, Jamal Yazji, Janette Mansour, Jean Arnautou, Jean Brocard, Jean Carolfi, Jean Montoriol, Jean Baptiste Gouin, Jean Bernard Palcoux, Jean Christophe Bendini, Jean Claude Aldigier, Jean Claude Alphonse, Jean Daniel Delbet, Jean Francois Bonne, Jean Francois Cantin, Jean Francois De Fremont, Jean Francois Dessassis, Jean Francois Subra, Jean Francois Valentin, Jean Francois Verdier, Jean Jacques Dion, Jean Jacques Haultier, Jean Jacques Montseny, Jean Louis Bacri, Jean Louis Bouchet, Jean Luc Mahe, Jean Marc Chalopin, Jean Marc Gabriel, Jean Marc Hurot, Jean Marc Lanau, Jean Marie Batho, Jean Marie Coulibaly, Jean Michel Hardin, Jean Michel Marc, Jean Michel Poux, Jean Michel Rebibou, Jean Michel Tivollier, Jean Noel Ottavioli, Jean Paul Faucon, Jean Paul Imiela, Jean Paul Jaulin, Jean Paul Masselot, Jean Paul Ortiz, Jean Philippe Bourdenx, Jean Philippe Devaux, Jean Philippe Hammelin, Jean Pierre Rivory, Jean Pierre Wauquier, Jean Rene Larue, Jean Rene Mondain, Jean Sebastien Borde, Jean Simon Virot, Jean Yves Bosc, Jedjiga Achiche, Jennifer Parasote, Jeremie Diolez, Jerome Harambat, Jerome Potier, Jerome Sampol, Jihad Mustel, Jean Jacques Lefevre, Jocelyne Maurizi, Joel Gamberoni, Joelle Claudeon, Joelle Terzic, Joffrey Rogol, Johnny Sayegh, Jorge Cardozo, Jose Brasseur, Jose Guiserix, Joseph Barsumau, Julie Albaret, Julie Beaume, Julie Sohier Attias, Julien Dehay, Julien Hogan, Julien Journet, Julien Ott, Juliette Baleynaud, Justine Bacchetta, Justine Faucher, Kamel Yousfi, Karim Dardim, Karine Clabault, Karine Moreau, Kedna Thomas, Khaled Sirajedine, Khalil Chedid, Khalil El Kaeoui, Khalil El Karoui, Khedidja Bouachi, Kheira Hue, Khuzama El Nasser, Kodso Akposso, Kristian Kunz, Krzysztof Bijak, Lilia Kihal, L. Rasoloarijaona, Laid Harbouche, Larbi Bencheikh, Larbie Lamriben, Latifa Hanafi, Laura Braun Parvez, Laure Champion, Laure Croze, Laure Eprinchard, Laure Patrier, Laurence Nicolet, Laurence Vrigneaud, Laurent Duflot, Leandre Mackaya, Leila Chenine, Leon Odry, Lili Taghipour Tamiji, Lilia Antri Bouzar, Liliane Ngango Nga Messi, Lionel Le Mouellic, Lise Mandart, Lise Weis, Lise Marie Pouteau, Lora Georgieva, Lorita Vitanova, Lotfi Chalabi, Luc Delvallez, Luc Fromentin, Luc Marty, Luc Monjot, Luciana Spataru, Lucie Bessenay, Lucie Boissinot, Lucie Wajsbrot, Lucien Rakoff, Ludivine Lebourg, Lydie Perez, Lyliane Lafage, Lynda Azzouz, Madeleine Dumoulin, Messaoud Ouziala, Maan Joseph, Mabrouk Brahimi, Maeva Wong Fat, Magalie Fort, Magued Nakhla, Mahdi Abtahi, Mahen Albadawy, Mahmoud Alouach, Mahmoud Mezghani, Maite Daroux, Maklouf Boukelmoune, Malek Dhib, Malik Touam, Malina Dubau, Mamadou Balde, Man Nguyen Khoa, Manfred Ismer, Manolie Mehdi, Manon Laforet, Marc Bouiller, Marc Eugene, Marc Fila, Marc Hazzan, Marc Kribs, Marc Ladriere, Marc Lebot, Marc Padilla, Marc Souid, Marcel Marraoui, Maren Burbach, Maria Manescu, Maria Eugenia Noguera Gonzalez, Mariana Revenco, Marianne Terrasse, Marie Essi, Marie Alice Macher, Marie Beatrice Nogier, Marie Cecile Cazin, Marie Christine Schweitzer Camoin, Marie Christine Thouret, Marie Claude Hannaert, Marie France Servel, Marie Helene Chabannier, Marie Jeanne Coudert Krier, Marie Noelle Catoliquot, Marie Paule Guillodo, Marie Sophie Gavard, Marie Xaviere Vairon Codaccioni, Marina Rabec, Marine Freist, Marion Gauthier, Marion Lemaire, Marion Mehrenberger, Marion Venot, Marios Pongas, Marlene Beaubrun Diant, Martial Levannier, Martine Bertaux, Mathieu Jablonski, Mathieu Sacquepee, Mathilde Dargelos, Mathilde Lemoine, Mathilde Tamain, Matthieu Monge, Matthieu Reberolle, Maud Cousin, Maud Francois, Maurice Baron, Maxime Hoffmann, Maxime Ingwiller, Maxime Touzot, Mederick Mohajer, Mehadji Maaz, Melanie Hanoy, Melanie Marroc, Melodie Cuny, Menno Van Der Straaten, Mf. Serveaux, Michel Basteri, Michel Fen Chong, Michel Hecht, Michel Massad, Michel Normand, Michel Olmer, Michel Tolani, Michel Tsimaratos, Michele Hemery, Michele Kessler, Miguel Esposito, Milad Shenouda, Mimi Kareche, Mina Khalili, Mirella Diaconita, Mohamad Khair Rifard, Mohamed Aladib, Mohamed Belmouaz, Mohamed Brahim, Mohamed Diouani, Mohamed Fodil Cherif, Mohamed Jamali, Mohamed Maghlaoua, Mohamed Meddeb, Mohamed Ramdane, Mohamed Rifaat, Mohamed Sharifull Islam, Mohamed Adnan Abbade, Mokhtar Amrandi, Mokhtar Chawki, Monica Ciobotaru, Monica Indrieis, Monique Chanas, Monique Hoarau, Monzer Tomeh, Moufida Bellou, Mouloud Bouzernidj, Mounia Ammor, Mounir Guergour, Mountassir Benzakour, Mourad Hachicha, Moussa Coulibaly, Mustafa Smati, Mustapha Al Morabiti, Mustapha Amirou, Myriam Isnard, Myriam Pastural, Myriam Pujo, Nourredine Boumendjel, Nabil Majbri, Nabila Goumri, Nadege Mingat, Nader Bassilios, Nadia Kerkeni, Nadia Sedrati, Nadia Soltani, Nadine Maroun, Nadine Neyrat, Nahn Luang, Najeh El Esper, Naji Ammar, Nasredine Ghali, Nasser Hamdini, Natacha Noel, Natacha Potelune, Nathalie Maisonneuve, Nathalie Pertuiset, Nathalie Raynal, Nathalie Vittoz, Nazim Terki, Nelly Castin, Nestor Nankeu, Nicolas Bouvier, Nicolas Keller, Nicolas Legros, Nicolas Peters, Nicolas Quirin, Nicole Lefrancois, Nicole Monnier, Nicole Rance, Niels Bruckmann, Noel Mertens, Nolwenn Lorcy, Olivia Gilbert, Olivier Coldefy, Olivier Drouineau, Olivier Dunand, Olivier Fritz, Olivier Imhoff, Olivier Kourilsky, Olivier Lavelle, Olivier Papin, Olivier Roques, Ophelie Le Maner, Oussamah Fikri Benbrahim, Pablo Antonio Erina Torres, Pablo Antonio Urena Torres, Paolo Malvezzi, Pascal Bindi, Pascal Cluzel, Pascal Fontanier, Pascal Wheatley, Pascale Depraetre, Pascale Dubosq, Pascale Halin, Pascale Sebahoun, Pascale Siohan, Pascale Testevuide, Patrice Deteix, Patrice Nolen, Patricia Hue, Patricia Lemarchand, Patrick Donnadieu, Patrick Fievet, Patrick Fohrer, Patrick Francais, Patrick Giraud, Patrick Hallonet, Patrick Henri, Patrick Michaut, Patrick Niaudet, Patrick Pauly, Patrick Thomas, Patrik Deleaval, Paul Finielz, Paul Stroumza, Paule Hardy Yverneau, Pauline Caillard, Pedro Palacin, Perrine Aubertin, Philippe Attias, Philippe Chauveau, Philippe Coindre, Philippe Coste, Philippe Dubot, Philippe Fournier, Philippe Hiernaux, Philippe Jousset, Philippe Lan Yue Wah, Philippe Lang, Philippe Le Cacheux, Philippe Martin Dupont, Philippe Michel, Philippe Mirgaine, Philippe Moriniere, Philippe Nicoud, Philippe Rieu, Philippe Rousseau, Philippe Sporer, Philippe Thorel, Philippe Vanhille, Philippe Vigeral, Philippe Zaoui, Pierre Bataille, Pierre Brignon, Pierre Filipozzi, Pierre Housset, Pierre Peyronnet, Pierre Ramperez, Pierre Vautrin, Pierre Alexandre Michel, Pierre Francois Westeel, Pierre Louis Carron, Pierre Yves Durand, Pierrot Parent, Piotr Seniuta, François Kuentz, Rabah Fraoui, Rachel Tetaz, Rachid Amaria, Rachid Bourouma, Rachid Djeffal, Rachida Nebbad, Radia Allal, Radu Dimulescu, Rafaat Boustani, Rafik Mesbah, Raifat Makdassi, Raji Diab, Raluca Puslenghea, Raoul Roura, Rateb Khayat, Raymond Azar, Raymond Frayssinet, Regine Monkam, Rehouni Boulahrouz, Remi Boudet, Renato Demontis, Renaud Gansey, Rene Cuvelier, Renee Schmitt, Reschad Noordally, Reynald Binaut, Rezkallah Latif, Richard Dufresne, Richard Montagnac, Richard Reade, Robert Genin, Robert Novo, Rocsana Fickl, Roger Dufresne, Roger Magnol, Roland Issautier, Romain Mortelette, Ronan Delaval, Ronan Lohro, Roseline M'barga, S. Beau, Clémentine Dupuis, Marie Jacques Vidil, Sabria Hacini, Said Dahmoune, Saliha Lekhal, Salima Ahriz Sakso, Salima Saksi, Salvatore Citarda, Samir Boubenider, Samuel Kassis, Sandra Verhille, Sandrine Genestier, Sandrine Muller, Saoussen Krid, Sarah Richter, Sebastien Delbes, Sebastien Mailliez, Sebastien Veillon, Sébastien Nony, Seddick Benarbia, Severine Beaudreuil, Sidi Ali Benyaghla, Simon Duquennoy, Simona Baluta, Simona Boncila, Sonia Mzoughi, Sonia Ribal, Sophie Acamer, Sophie Chauvet, Sophie Girerd, Sophie Ozenne, Sophie Parahy, Sophie Rubens Duval, Sophie Taque, Soraya Menouer, Soumaya Chargui, Stanislas Bataille, Stephane Barbier, Stephane Billion, Stephane Roueff, Stephane Torner, Stephane Jean Martin, Stephanie Coupel, Sylvie Cloarec, Sylvie Lavaud, Sylvie Leou, T. Chatelet, Tania Onesta, Tassadit Benhabib, Tayeb Bensalem, Theodora Dimulescu, Theophile Sawadogo, Thibault Dolley Hitze, Thierry Baranger, Thierry Boudemaghe, Thierry Hannedouche, Thierry Krummel, Thierry Milcent, Thomas Dervaux, Thomas Guincestre, Thomas Kofman, Thomas Raphael, Thomas Sadreux, Tim Ulinski, Tiphaine Guyon Roger, Tomas Serrato, Tomek Kofman, Tony Wong, Toufik Boubia, Ubald Assogba Gbindoun, Usama Khuzaie, Valerie Caudwell, Valerie Chatelet, Valerie Crougneau, Valerie De Precigout, Valerie Drouillat, Valerie Galantine, Valerie Granveau Hugot, Valerie Leroy, Veronique Boubia, Veronique Falque, Veronique Fournier, Veronique Queron, Veronique Viviani, Victor Gueuttin, Victor Panescu, Victorio Menoyo Calonge, Viet Nguyen, Vincent Allot, Vincent Delattre, Vincent Leduc, Vincent Pradier, Violaine Emal Aglae, Viorica Badulescu, Virginia Molina, Virginie Besson, Virginie Chaigne, Waddah Jaber, Wael Boudi, Wael El Haggan, Wen Qin Guillon, Wided Tabbi Aneni, William Hanf, Wladimir Kohn, Xavier Bellenfant, Xavier Moreau Gaudry, Yahsou Delmas, Yannick Knefati, Yannick Saingra, Yannick Tirolien, Youssef Mann, Yvan Brunak, Yves Dimitrov, Yves Doussy, Yves Tanter, Zaid Benabid, Zaara Soltani, Zacharia Boukerroucha, Zafer Takla, Zana Ramanantsialonina, Zara Dickson, Zead Tubail, Zoe Koochaki Pour, Zohra Boukhalfa, Zohra Jacquot, Agence de la biomédecine [Saint-Denis la Plaine], Centre Hospitalier Régional Universitaire de Nancy (CHRU Nancy), Université de Caen Normandie (UNICAEN), Normandie Université (NU), CALYDIAL Vienne, Partenaires INRAE, Centre hospitalier universitaire de Nantes (CHU Nantes), Hôpital Armand Trousseau [AP-HP] (AP-HP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Centre recherche en CardioVasculaire et Nutrition = Center for CardioVascular and Nutrition research (C2VN), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre de néphrologie et transplantation rénale [Hôpital de la Conception - APHM], Assistance Publique - Hôpitaux de Marseille (APHM)-Hôpital de la Conception [CHU - APHM] (LA CONCEPTION), Service d'Epidémiologie et Evaluations Cliniques [CHRU Nancy] (Pôle S2R), Centre Universitaire des Maladies Rénales [CHU Caen] (CUMR Caen), Normandie Université (NU)-Normandie Université (NU)-CHU Caen, Normandie Université (NU)-Tumorothèque de Caen Basse-Normandie (TCBN)-Tumorothèque de Caen Basse-Normandie (TCBN), Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Institut de Génomique Fonctionnelle (IGF), Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS), Groupe hospitalier de la région de Mulhouse Sud-Alsace (GHRMSA), Centre Hospitalier Universitaire de Nîmes (CHU Nîmes), Aide à la Décision pour une Médecine Personnalisé - Laboratoire de Biostatistique, Epidémiologie et Recherche Clinique - EA 2415 (AIDMP), Université Montpellier 1 (UM1)-Université de Montpellier (UM), Assistance Publique - Hôpitaux de Marseille (APHM), Service de diabétologie [CHU Pitié-Salpétrière], CHU Pitié-Salpêtrière [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), CHU Caen, Normandie Université (NU)-Tumorothèque de Caen Basse-Normandie (TCBN)-Normandie Université (NU)-Tumorothèque de Caen Basse-Normandie (TCBN)-Université de Caen Normandie (UNICAEN), Service de Diabétologie [CHU Pitié-Salpétrière], and Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)

Subjects
0301 basic medicine, Male, medicine.medical_treatment, [SDV]Life Sciences [q-bio], 030232 urology & nephrology, Hemodialysis, Home, Disease, MESH: COVID-19 / therapy, registry, Ambulatory Care Facilities, [SDV.MHEP.UN]Life Sciences [q-bio]/Human health and pathology/Urology and Nephrology, MESH: Aged, 80 and over, 0302 clinical medicine, [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases, Risk Factors, 80 and over, Prevalence, covid, dialysis, epidemiology, mortality, Aged, Aged, 80 and over, COVID-19, Case-Control Studies, Critical Care, Female, France, Humans, Incidence, Middle Aged, Patient Acuity, Protective Factors, Registries, Renal Dialysis, SARS-CoV-2, Sex Factors, Hypoalbuminemia, MESH: France / epidemiology, education.field_of_study, Incidence (epidemiology), 3. Good health, MESH: COVID-19 / epidemiology, Nephrology, Hemodialysis, medicine.medical_specialty, Population, Lower risk, Article, 03 medical and health sciences, MESH: Sex Factors, Internal medicine, medicine, MESH: SARS-CoV-2, MESH: Renal Dialysis / statistics & numerical data, education, Dialysis, Vascular disease, business.industry, medicine.disease, Former Smoker, MESH: Critical Care / statistics & numerical data, 030104 developmental biology, [SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie, business, Home, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology, MESH: Hemodialysis, Home / statistics & numerical data
Abstract

The aim of this study was to estimate the incidence of COVID-19 disease in the French national population of dialysis patients, their course of illness and to identify the risk factors associated with mortality. Our study included all patients on dialysis recorded in the French REIN Registry in April 2020. Clinical characteristics at last follow-up and the evolution of COVID-19 illness severity over time were recorded for diagnosed cases (either suspicious clinical symptoms, characteristic signs on the chest scan or a positive reverse transcription polymerase chain reaction) for SARS-CoV-2. A total of 1,621 infected patients were reported on the REIN registry from March 16th, 2020 to May 4th, 2020. Of these, 344 died. The prevalence of COVID-19 patients varied from less than 1% to 10% between regions. The probability of being a case was higher in males, patients with diabetes, those in need of assistance for transfer or treated at a self-care unit. Dialysis at home was associated with a lower probability of being infected as was being a smoker, a former smoker, having an active malignancy, or peripheral vascular disease. Mortality in diagnosed cases (21%) was associated with the same causes as in the general population. Higher age, hypoalbuminemia and the presence of an ischemic heart disease were statistically independently associated with a higher risk of death. Being treated at a selfcare unit was associated with a lower risk. Thus, our study showed a relatively low frequency of COVID-19 among dialysis patients contrary to what might have been assumed., Graphical abstract

Published
2020
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90. Nanoscale oxidation behavior of carbon fibers revealed with in situ gas cell STEM

Author

Raymond R. Unocic, Thomas J. Cochell, José Graña-Otero, and Alexandre Martin

Subjects
In situ, bepress|Engineering|Nanoscience and Nanotechnology, Materials science, Thin section, bepress|Engineering, Carbon fibers, bepress|Engineering|Mechanical Engineering, engrXiv|Engineering|Mechanical Engineering, bepress|Engineering|Aerospace Engineering, 02 engineering and technology, engrXiv|Engineering|Mechanical Engineering|Heat Transfer, 01 natural sciences, bepress|Engineering|Aerospace Engineering|Space Vehicles, 0103 physical sciences, Scanning transmission electron microscopy, engrXiv|Engineering|Aerospace Engineering|Space Vehicles, engrXiv|Engineering|Aerospace Engineering|Astrodynamics, engrXiv|Engineering|Mechanical Engineering|Combustion, General Materials Science, Nanoscopic scale, 010302 applied physics, Mechanical Engineering, Metals and Alloys, Active surface, 021001 nanoscience & nanotechnology, Condensed Matter Physics, engrXiv|Engineering|Aerospace Engineering, engrXiv|Engineering|Nanoscience and Nanotechnology, bepress|Engineering|Mechanical Engineering|Heat Transfer, Combustion, Chemical engineering, engrXiv|Engineering, engrXiv|Engineering|Aerospace Engineering|Structures and Materials, Mechanics of Materials, Atmospheric entry, bepress|Engineering|Aerospace Engineering|Astrodynamics, visual_art, visual_art.visual_art_medium, Crystallite, bepress|Engineering|Materials Science and Engineering, engrXiv|Engineering|Materials Science and Engineering, bepress|Engineering|Aerospace Engineering|Structures and Materials, 0210 nano-technology
Abstract

Thermal protection systems (TPS) are used to protect spacecraft payloads during the extreme conditions of atmospheric entry. The backbone of the composite TPS material used in the NASA Stardust Sample Return Capsule and the Mars 2020 mission is carbon fiber, which oxidizes at these temperatures and atmospheric conditions. This study presents the direct observation of carbon oxidation using in situ Scanning Transmission Electron Microscopy (STEM). A thin section of a commercially-available carbon fiber material containing multiple carbon structures was examined by STEM in a closed-environmental cell in which temperature was raised from 25 to 1050àC under a steady flow of air. Results show that the random polycrystalline carbon structure oxidized more uniformly and rapidly than the single crystallite region, which oxidized more anisotropically. These findings are the first to directly observe the structural dependence of carbon oxidation rates at these length-scales while also giving important insight into the onset of pitting at various active surface sites, important pieces in fundamentally understanding of carbon oxidation.

Published
2020

91. Permeability calculation of a fibrous thermal insulator using the Lattice Boltzmann method

Author

Michel Ho, Marcelo Reggio, Jean-Yves Trépanier, Alexandre Martin, and Sébastien Leclaire

Subjects
Materials science, bepress|Engineering, engrXiv|Engineering|Mechanical Engineering|Fluid Mechanics, bepress|Engineering|Mechanical Engineering, engrXiv|Engineering|Mechanical Engineering, Lattice Boltzmann methods, 0207 environmental engineering, Aerospace Engineering, bepress|Engineering|Aerospace Engineering, Richardson extrapolation, 02 engineering and technology, engrXiv|Engineering|Mechanical Engineering|Heat Transfer, 010502 geochemistry & geophysics, 01 natural sciences, 010305 fluids & plasmas, bepress|Engineering|Aerospace Engineering|Space Vehicles, 0203 mechanical engineering, Thermal insulation, engrXiv|Engineering|Aerospace Engineering|Space Vehicles, 0103 physical sciences, engrXiv|Engineering|Aerospace Engineering|Astrodynamics, Fluid dynamics, 020701 environmental engineering, 0105 earth and related environmental sciences, Fluid Flow and Transfer Processes, Computer simulation, business.industry, Mechanical Engineering, Mechanics, Condensed Matter Physics, Boltzmann equation, engrXiv|Engineering|Aerospace Engineering, bepress|Engineering|Mechanical Engineering|Heat Transfer, Combustion, 020303 mechanical engineering & transports, engrXiv|Engineering, bepress|Engineering|Aerospace Engineering|Astrodynamics, Space and Planetary Science, bepress|Engineering|Aerospace Engineering|Aerodynamics and Fluid Mechanics, Direct simulation Monte Carlo, business, Porous medium
Abstract

The Lattice Boltzmann method is used to compute the permeability of FiberForm, a fibrous thermal insulator commonly used as the substrate of thermal protection systems materials. The results are compared to experiment and numerical results that uses another approach. The Lattice Boltzmann approach proves to be as accurate as other computational methods but shows a computational cost that is orders of magnitude smaller.

Published
2020
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95. A review of simulated climate change impacts on groundwater resources in Eastern Canada

Author

Marie Larocque, Diane Chaumont, Jana Levison, and Alexandre Martin

Subjects
Effects of global warming, business.industry, Snowmelt, Climate change scenario, Water supply, Environmental science, Climate change, Climate model, Groundwater recharge, Water resource management, business, Groundwater, Water Science and Technology
Abstract

In Eastern Canada, groundwater is the main water supply for most of the rural regions and in many large urban communities. An understanding of the impacts of climate change on this resource is crucial for sustainable water management in this region. The objectives of this paper was to summarize the state of knowledge about possible climate change impacts on groundwater dynamics in Eastern Canada, thus providing a clearer understanding of future conditions. Twenty-two studies are reviewed including Ontario, Quebec, New Brunswick, Nova Scotia, and Prince Edward Island, to identify the impacts on groundwater recharge and river baseflows. The studies disagree in their estimates of changes in future recharge conditions, and no trend from West to East was revealed. This could be due to the use of different modelling approaches (model type, climate change scenario, future horizon). Nonetheless, more inter-annual variability during the summer and earlier snowmelt periods causing seasonal shifts in the recharge cycle are expected. The studies show that base flows could decrease, which could induce critical conditions for water supplies and for ecosystems. This review provided new insights that lead to the following recommendations for future studies: 1) use a variety of climate models and emission scenarios; 2) promote the use of integrated models when possible; 3) study long-term climate change impacts on groundwater resources at different scales; 4) simulate the combined effects of climate change and other pressures; and 5) develop models that cover other regions of Eastern Canada as dictated by stakeholders and water managers.

Published
2019
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96. Arc-jet measurements of low-density ablator spallation

Author

Kristen J. Price, Francesco Panerai, Colby G. Borchetta, J. Matthew Hardy, Alexandre Martin, and Sean C.C. Bailey

Subjects
Fluid Flow and Transfer Processes, Nuclear Energy and Engineering, Mechanical Engineering, General Chemical Engineering, Aerospace Engineering
Published
2022
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97. Numerical analysis of time accuracy of a primitive variable-based formulation of the conservative form of the governing equations for compressible flows

Author

Alexandre Martin, Huaibao Zhang, and Guangxue Wang

Subjects
business.industry, Mechanical Engineering, Numerical analysis, Computational Mechanics, Energy Engineering and Power Technology, Aerospace Engineering, Computational fluid dynamics, Condensed Matter Physics, 01 natural sciences, Wedge (geometry), Compressible flow, 010305 fluids & plasmas, Euler equations, 010101 applied mathematics, symbols.namesake, Mechanics of Materials, 0103 physical sciences, Compressibility, symbols, Applied mathematics, 0101 mathematics, business, Shock tube, Variable (mathematics), Mathematics
Abstract

A class of Computational Fluid Dynamics codes uses primitive variable-based formulation to solve the conservative form of the governing equations. Under certain specific conditions, the approach yields inaccurate results for unsteady problems. Here, Euler equations are used to numerically analyse time accuracy when using such an approach. It is demonstrated, using a simple shock tube problem, that the primitive variable-based approach does not strictly preserve time accuracy. A dual-time stepping technique, which uses an inner iteration of pseudo-time within the physical time, is used to correct the issue. The method is applied to the shock tube problem, which eliminates the time-dependent discrepancies. The problem, and the correction, is also applied to a supersonic flow over a wedge. In both cases, the results are shown to be identical to the solution obtained using a conservative variable-based approach.

Published
2018
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98. 3D coupled HM–XFEM modeling with cohesive zone model and applications to non planar hydraulic fracture propagation and multiple hydraulic fractures interference

Author

P. Massin, Alexandre Martin, Maxime Faivre, Daniele Colombo, Bertrand Paul, Richard Giot, Fabrice Golfier, Institut des Sciences de la mécanique et Applications industrielles (IMSIA - UMR 9219), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), GeoRessources, Institut national des sciences de l'Univers (INSU - CNRS)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), IFP Energies nouvelles (IFPEN), ANR-17-CE06-0016,HydroGeoDam,Vers une meilleure évaluation de l'impact de l'endommagement hydraulique pour les applications de géo-ingénierie(2017), ANR-10-LABX-0021,RESSOURCES21,Strategic metal resources of the 21st century(2010), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-EDF R&D (EDF R&D), and Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
fracture spacing, cohesive zone model, fracture interference, Poromechanics, 0211 other engineering and technologies, Computational Mechanics, General Physics and Astronomy, 02 engineering and technology, X-FEM, [SPI.MECA.SOLID]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Solid mechanics [physics.class-ph], 01 natural sciences, Physics::Geophysics, Physics::Fluid Dynamics, hydro-mechanical coupling, Discontinuity (geotechnical engineering), Fluid dynamics, 0101 mathematics, fluid-driven fracture, 021101 geological & geomatics engineering, Extended finite element method, complex fracture, Biot number, Mechanical Engineering, Mechanics, Computer Science Applications, 010101 applied mathematics, Cohesive zone model, Mechanics of Materials, Lubrication, Porous medium, Geology
Abstract

A 3D fully coupled hydromechanical model for the simulation of fluid-driven fracture propagation through poroelastic saturated media is presented and compared to several analytical or numerical benchmarks. The hydromechanical coupling in the porous matrix is derived within the framework of the generalized Biot theory and the fluid flow in the fractures satisfies the lubrication equation. The presence and propagation of fluid-driven fractures is handled with the extended finite element method and the propagation of the fluid-driven fractures is governed by a mixed linear cohesive law relying on a stable mortar formalism. A comparison between numerical results and a semi-analytical solution for plane fluid-driven fractures in porous media assess the validity of the proposed model. Then, a procedure for the propagation of fluid-driven fractures on non predefined paths is detailed. In particular, the fracture reorientation angle is computed exclusively from cohesive quantities. Various numerical experiments are performed to study the interferences between neighboring fluid-driven fractures as well as the reorientation of fluid-driven fractures under complex stress conditions. Finally, the model is extended to discontinuity junctions and an application to arrays of vertical fractures initiated from horizontal wells is presented.

Published
2018
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100. Experimental analysis of spallation particle trajectories in an arc-jet environment

Author

Sean C. C. Bailey, Francesco Panerai, Dominik Bauer, Paul M. Danehy, Alexandre Martin, Scott C. Splinter, and J. Matthew Hardy

Subjects
Fluid Flow and Transfer Processes, 020301 aerospace & aeronautics, Jet (fluid), Hypersonic speed, Materials science, Mechanical Engineering, General Chemical Engineering, medicine.medical_treatment, Airflow, Aerospace Engineering, 02 engineering and technology, Mechanics, Ablation, 01 natural sciences, 010305 fluids & plasmas, 0203 mechanical engineering, Nuclear Energy and Engineering, Atmospheric entry, 0103 physical sciences, Heat shield, medicine, Particle, Spallation
Abstract

Spallation is a phenomenon in which solid particles are ejected off the surface of an ablative material in a high-enthalpy, high-shear flow field. The main contributor to this phenomenon in carbon-based heat shields is the mechanical erosion of carbon fibers weakened by oxidation decomposition. The dynamics of this phenomenon, which are poorly characterized in the literature, strongly affect the ablation rate of the material. In state-of-the-art codes, ablation by spallation is modeled using a “failure” ablation rate that is empirically determined. The present study aims at understanding the rate of ablation of low-density carbon materials. Results from a test campaign at the NASA Langley Hypersonic Materials Environmental Test System (HYMETS) arc jet facility are used to examine spallation. High-speed multi-camera imagery at 44,000 fps is used to generate velocity vectors of spalled particles emitted from carbon-fiber samples exposed to an arc jet airflow. The imagery recorded approximately 4 × 10 6 unique particles, indicating that spallation is a potentially non-trivial process. The velocities of the particles ejected from the surface were found to be between 10 m/s and 20 m/s, accelerating to velocities as high as 250 m/s further away from the sample surface. Although the particle diameters were not directly observable, estimates suggest anywhere from 0.06% to 5.6% of the mass loss from the sample occurred due to spallation.

Published
2018
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