Academic literature on the topic 'Interaction choc'
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Journal articles on the topic "Interaction choc"
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Chpoun, Amer, Franck Chauveau, Loup Zombas, and Gabi Ben-Dor. "Les interaction d'ondes de choc coniques." Comptes Rendus de l'Académie des Sciences - Series IIB - Mechanics-Physics-Astronomy 327, no. 1 (January 1999): 85–90. http://dx.doi.org/10.1016/s1287-4620(99)80014-3.
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Gouidmi, Hamza, Razik Benderradji, and Abdelhadi Beghidja. "Numerical Simulation of the Interaction Shock/Turbulent Boundary." Key Engineering Materials 550 (April 2013): 171–78. http://dx.doi.org/10.4028/www.scientific.net/kem.550.171.
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This study is fulfilled to simulate numerically the interaction phenomenon of the bidimensional compressible and supersonic flow with M=2.28 of a turbulent boundary layer with an oblique choc wave. The oblique choc wave is released and oriented by a generator of choc in an angle of θw=8° on a plate plane maintained at a constant temperature. The interaction causes the detachment of the boundary layer and make it disturbed (The case of experimental study done by J. Deleuze (1995)). The contribution on the effects of turbulence and their characteristics is represented by k-w-SST model. This model is well adapted for this type of application. This study permits to underline the coherence of our analysis with existant numerical and experimental results. This simulation is effected by means of solver which based on the spatio-temporal discretization of the complex equations of Navier-Stockes with finite volumes method. We also use the Upwind scheme of second order.
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Gouidmi, Hamza, Abdelhadi Beghidja, Razik Benderradji, Nabila Ihaddadène, and Elhadj Raouache. "Etude numérique d’une structure de choc Phénomène d’interaction choc/couche limite." Journal of Renewable Energies 20, no. 3 (September 30, 2017): 397–413. http://dx.doi.org/10.54966/jreen.v20i3.636.
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Dans une certaine plage de nombre de Mach, l'interaction entre une onde de choc oblique et une couche limite s'effectue par une investigation numérique sur une plaque plane athermane, basée sur la résolution des équations de Navier-Stokes bidimensionnelles par le code Fluent. Cette interaction se matérialise sous la forme d'une onde de choc en 'lambda', décrite en premier par Mark en 1958. Elle peut être rencontrée dans les équipements des souffleries à haute enthalpie ou ceux relatifs à la distribution de gaz comprimés par exemple. Une bonne connaissance des phénomènes physiques intervenant dans de tels écoulements est nécessaire tant au point de vue des normes de sécurité qu'en terme d'accroissement des performances. Sous cette structure de choc, il se forme un bulbe de décollement massif engendrant une succession de structures tourbillonnaires en cas laminaire que turbulent due par l’effet du nombre de Mach amont qui est observé. Elle est suivie par un phénomène de transition de la réflexion régulière RR vers la réflexion de Mach MR pour le cas turbulent. Globalement les résultats numériques obtenus sont conformes avec ceux qui sont disponibles dans la littérature.
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FARGERE, N. "INTERACTION CHOC-SURFACE LIQUIDE : COMPARAISON CODE DE CAVITATION ET EXPÉRIMENTATION." Le Journal de Physique IV 01, no. C3 (October 1991): C3–893—C3–897. http://dx.doi.org/10.1051/jp4:19913125.
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Hugoson, Rolf. "Clarifying Liquidity." Contributions to the History of Concepts 14, no. 2 (December 1, 2019): 46–66. http://dx.doi.org/10.3167/choc.2019.140203.
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This article is a history of liquidity presented as interaction between metaphors and theoretical concepts in social contexts. While taking note of Zygmunt Bauman’s metaphor “liquid modernity,” the study instead surveys the wider conceptual field. The text turns around mercantile liquidity (liquidity as clarification) and liquidity in modern economics (characteristic of all assets), as well as older metaphors, notably the famous phrase of the Communist Manifesto, “all that is solid melts into air” (Alles Ständische und Stehende verdampft), which is revealed to have resonance in texts by poets, notably Heinrich Heine. The main result is the historical consistency of the field, where liquidity is a promise of knowledge and clarity.
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Bryan, Joseph D. "Beyond Metaphor." Contributions to the History of Concepts 15, no. 2 (December 1, 2020): 29–50. http://dx.doi.org/10.3167/choc.2020.150203.
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Body-politic metaphors served historically as figurative vehicles to transmit assorted socio-political messages. Through an examination of the metaphors la mollesse (softness) and Adam Smith’s impartial spectator, this article will show that the language of eighteenth-century French and British writers was not simply heuristic or metaphorical. Contemporaries reacted to the growth of commerce and luxury, and the concomitant creation of new public spaces and forms of social interaction, by arguing that the corporeal mediated the social. I want to introduce the concept of corporeal sociability: cognitive physiology and the network of the senses, contemporaries argued, contained the information necessary to assess novel forms of commerce and revealed that sociability was congenitally embodied.
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Schäfer, Rieke. "Historicizing Strong Metaphors." Contributions to the History of Concepts 7, no. 2 (December 1, 2012): 28–51. http://dx.doi.org/10.3167/choc.2012.070202.
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The debate between metaphor theorists and conceptual historians has been intensifying in recent years. This article takes this debate beyond the bias toward Blumenberg's metaphorology, and starts from the interaction view of metaphor as formulated by Max Black. The article opens with a theoretical framework that reformulates Black's notions of metaphorical resonance and emphasis. It adapts them to the requirements of Conceptual History, and adds a third, historical criterion for metaphoricity. It then applies these suggestions to the history of the metaphor play/game/Spiel/jeu within twentieth-century political thought. Here, the focus lies on the role this metaphor plays in the conceptual relations between the ideas of political order, conflict, and immanence.
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Surman, Jan, Katalin Stráner, and Peter Haslinger. "Nomadic Concepts." Contributions to the History of Concepts 9, no. 2 (December 1, 2014): 1–17. http://dx.doi.org/10.3167/choc.2014.090201.
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This article introduces a collection of studies of biological concepts crossing over to other disciplines and nonscholarly discourses. The introduction discusses the notion of nomadic concepts as introduced by Isabelle Stengers and explores its usability for conceptual history. Compared to traveling (Mieke Bal) and interdisciplinary (Ernst Müller) concepts, the idea of nomadism shifts the attention from concepts themselves toward the mobility of a concept and its effects. The metaphor of nomadism, as outlined in the introduction, helps also to question the relation between concepts' movement and the production of boundaries. In this way conceptual history can profit from interaction with translation studies, where similar processes were recently discussed under the notion of cultural translation.
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Araújo Neto, Luiz Alves. "Cancer Prevention in Brazil." Contributions to the History of Concepts 17, no. 2 (December 1, 2022): 1–17. http://dx.doi.org/10.3167/choc.2022.170201.
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This article discusses possible dialogues between medical history and the history of concepts, suggesting that a “socio-conceptual-moral” history of medicine offers insightful elements for the historical analysis of conceptual change. Drawing mainly from Reinhart Koselleck’s Begriffsgeschichte and Ludwik Fleck’s theory of knowledge, I focus on three points of the “socio-conceptual-moral” perspective: the approach to medical statements as part of a semantic field, the interaction between a formulated concept and its practice, and negotiations about the meanings of medical concepts between different social arenas. I take the history of cancer prevention in Brazil as a case study to discuss these three aspects and emphasize the situated character of conceptual change. The article analyzes the period between the 1960s and the 1990s when substantial changes in the conceptual framework of cancer prevention confronted continuities in public health and medicine practices, policies, and institutions.
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Morgan, Lee Roy, Mansour Mathkour, Juanita Garces, Edmund N. Benes, Andrew H. Rodgers, Brando S. Jursic, R. F. Struck, et al. "EXTH-57. INTERACTION OF 4-DEMETHYL-4-CHOLESTERYLOXYCARBONYLPENCLOMEDINE (DM-CHOC-PEN) WITH MELANOMA MELANIN METABOLISM AND CELL DEATH." Neuro-Oncology 18, suppl_6 (November 1, 2016): vi71. http://dx.doi.org/10.1093/neuonc/now212.299.
Full textDissertations / Theses on the topic "Interaction choc"
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Duquesne, Nathalie. "Modélisation et simulation numérique d'une interaction choc-choc tridimensionnelle en écoulement hypersonique turbulent." Poitiers, 1995. http://www.theses.fr/1995POIT2340.
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Cette etude a ete consacree a la modelisation et a la simulation numerique d'une interaction choc-choc tridimensionnelle dans un ecoulement de gaz parfait en regime laminaire et turbulent. La configuration retenue afin de modeliser cette interaction est constituee d'un cylindre en fleche soumis a l'interaction d'un choc oblique induit par un diedre place au meme angle de fleche. Les positions relatives du diedre et du cylindre ont ete choisies de facon a obtenir une interaction de type iv dans la classification de edney, interaction generalement associee aux flux de chaleur les plus importants. Les equations de navier-stokes moyennees sont fermees par le modele algebrique de baldwin-lomax et par les differents modeles ( - ) bas-reynolds de chien, hoffmann, jones-launder et zhang. La methode numerique utilisee repose sur une formulation de type volumes finis definie sur des maillages structures. Les termes non visqueux sont traites au moyen d'un schema tvd symetrique de yee et les termes visqueux sont discretises par un schema aux differences finies centre du second ordre. Les experiences realisees sur cette configuration a un nombre de mach de 7. 14 ont indique un etat laminaire de l'ecoulement sur le cylindre seul, et turbulent dans le cas de l'interaction. Neanmoins un etat turbulent de l'ecoulement sur le cylindre seul a pu etre obtenu en placant normalement a la ligne d'attachement un fil de declenchement. Pour ce cas, les resultats numeriques et experimentaux ont ete en tres bon accord pour la majorite des modeles. De plus larges differences ont ete relevees dans le cas de l'interaction, la localisation du pic principal de flux a ete correctement predite par le calcul, en revanche, la valeur du pic de flux semble etre sur-estimee
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Aymer, de la Chevalerie Dominique. "Interaction onde de choc-couche limite modélisation et calcul." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37595581g.
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MNIF, MAHER. "Interaction de deux ondes de choc pour une loi de conservation." Paris 11, 1994. http://www.theses.fr/1994PA112032.
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Pour le probleme de riemann associe a une loi de conservation scalaire hyperbolique d'ordre deux avec donnees initiales h#s de part et d'autre d'une hypersurface s#0, on demontre l'existence et la stabilite de deux ondes de chocs issues de s#0. Avec une transformation d'hodographe partielle speciale, ce probleme se ramene a l'etude d'un probleme de goursat scalaire quasi lineaire hyperbolique, pour lequel l'existence et la stabilite d'une solution sont prouvees par un schema iteratif lineaire. L'estimation d'energie est obtenue par la methode de garding qui repose sur un choix convenable de multiplicateurs. L'etude de l'interaction de deux chocs releve des memes techniques et se ramene a un probleme de goursat
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Raimbaud, Quentin. "Interaction entre une onde de choc et un film de savon." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S103.
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De nombreux travaux ont permis de montrer que les mousses ont la capacité d’atténuer fortement les effets des ondes de choc. Cependant, bien que de nombreuses théories aient été proposées, les mécanismes physiques à l’origine de cette atténuation restent majoritairement inconnus. Dans le cadre de cette thèse, afin de simplifier problème, nous avons décidé d’étudier en particulier l’interaction entre une onde de choc et l’un des composants élémentaires de la mousse : le film de savon. Pour cela, nous avons dimensionné et fabriqué un tube à choc modulaire qui nous permet de générer des ondes de choc avec différents profils de pression et de les faire interagir avec de nombreuses configurations de films de savon. Nous avons commencé par étudier l’accélération d’un film de savon impacté par une onde de choc parallèle au film. Nous avons observé la réflexion et la transmission de l’onde de choc incidente et étudié le mouvement du film afin de déterminer son temps d’accélération et sa vitesse terminale. Nous avons ensuite étudié l’effet des gradients d’épaisseur dans le film lors de la phase d’accélération . Nous avons développé un modèle permettant d’expliquer les différences comment ces gradients influencent la rupture du film.Pour finir, nous avons étudié l’interaction entre une onde de choc et un film, si celui ci n’est pas parallèle au choc. Nous avons alors observé l’apparition d’une instabilité de Kelvin-Helmholtz sur le film avant sa ruptureNumerous works have proven that liquid foams significantly attenuate shockwaves. However, even though many theories have been developed, the underlying mechanisms behind this attenuation remains mostly unknown. For the sake of simplicity, we studied the interaction between shockwaves and one of the base elements of foam: foam films. To generate the shockwaves we needed, we created a modular shocktube that allows us to modify both the shape of the pressure signal and the orientation of the films. We started by studying the acceleration of a single foam film impacted by a parallel shockwave. We observed the reflexion and transmission of the shockwave and the movement of the film, which allowed us to get the film’s acceleration time and terminal velocity. We then studied the effects of thickness gradients within the film during the acceleration phase. We developed a model to explain how these gradients affect the breaking of the films. Finally, we studied the interaction between a shockwave and a film, when the two are not parallel to each other. We observed the development of a Kelvin-Helmholtz instability in the film before its rupture
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HADDAD, Christian. "Instationnarités, mouvements d'onde de choc et tourbillons à grandes échelles dans une interaction onde de choc / couche limite avec décollement." Phd thesis, Université de Provence - Aix-Marseille I, 2005. http://tel.archives-ouvertes.fr/tel-00008394.
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Une étude expérimentale a été effectuée sur une configuration d'interaction à Mach 2.3 entre un choc incident et une couche limite turbulente (réflexion de choc oblique sur paroi plane) engendrant un décollement suivi d'un recollement, en vue de comprendre les phénomènes physiques mis en jeu dans ce type d'interaction : apparition et entretien de basses fréquences. Pour cela, l'organisation spatiale et temporelle de cet écoulement a été examinée pour différents angles de déflexion du générateur de choc (de 7 à 9.5°). Les données en paroi ou en champ en un ou plusieurs points proviennent de mesures effectuées à l'aide de capteurs de pression ou par anémométrie à fil chaud. L'analyse de ces données a permis de caractériser les différentes zones : le choc réfléchi instationnaire est animé d'un mouvement basse fréquence, avec des longueurs d'excursion variant d'une à deux fois l'épaisseur de couche limite initiale, cette longueur s'atténuant à l'extérieur de la couche. La construction d'une fréquence adimensionnelle associée aux oscillations basses fréquences du choc réfléchi (nombre de Strouhal) a permis de regrouper l'ensemble des résultats ainsi que ceux obtenus dans la littérature pour d'autres configurations d'interaction. Le décollement présente de grandes similitudes avec les décollements subsoniques, avec toutefois certaines spécificités propres à la compressibilité de notre écoulement. L'étude des connexions entre le choc réfléchi instationnaire et le décollement ont permis de revisiter les mécanismes proposés dans des configurations d'interaction différentes qui expliquent la nature de ces liaisons. Par ailleurs, l'organisation transversale du décollement a été explorée à l'aide de mesures effectuées par Vélocimétrie par Images de Particules (PIV) et a mis en évidence, pour les décollements les plus intenses, deux tourbillons contra-rotatifs de type trombe se développant au cœur de la zone de recirculation et dont les fréquences de rotation moyennes déterminées en paroi sont voisines de celles du choc réfléchi.
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Haddad, Christian. "Instationnarités, mouvements d'onde de choc et tourbillons à grandes échelles dans une interaction onde de choc / couche limite avec décollement." Aix-Marseille 1, 2005. http://www.theses.fr/2005AIX11003.
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Une étude expérimentale effectuée à Mach 2. 3 dans une interaction choc oblique-couche limite turbulente avec décollement pour plusieurs angles de déflexion de l'écoulement a permis de caractériser différentes régions en termes d'échelles de temps et d'espace : le choc réfléchi instationnaire oscillant à basse fréquence sur des longueurs d'excursion variant en paroi d'une à deux fois l'épaisseur de couche limite et une fréquence adimensionnelle associée regroupant les résultats et ceux obtenus dans d'autres configurations d'interaction. Le décollement présente de fortes similitudes avec les décollements subsoniques, avec certaines spécificités de compressibilité. L'étude des connexions entre le choc instationnaire et le décollement a permis de revisiter les mécanismes proposés dans la littérature. L'organisation transversale du décollement a révélé à l'aide de mesures PIV, deux tourbillons trombe contra-rotatifs aux fréquences de rotation voisines de celles caractérisant le choc réfléchi.
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Solakoglu, Erhan. "Modélisation des écoulements compressibles turbulents. Interaction onde de choc/couche limite turbulente." Rouen, 1994. http://www.theses.fr/1994ROUES023.
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Le travail présenté dans ce mémoire est consacré à la modélisation de la turbulence, étudiée dans le cadre particulier de la simulation d'interactions onde de choc/couche limite. Les cas-tests étudiés sont: canal transsonique 2D avec bosse à la paroi, écoulement supersonique 2D sur une marche montante et canal transsonique 3D avec bosse en flèche. Les modèles de turbulence utilisés sont: modèle algébrique de Baldwin-Lomax et modèle k-epsilon de Jones-Launder. Une revue bibliographique fait l'objet du premier chapitre. Le deuxième chapitre développe des équations de Navier-Stokes, moyennées au sens de Favre. Le problème de la fermeture des équations moyennées et les différents modèles de turbulence sont présentés dans le troisième chapitre. Dans le quatrième chapitre, la méthode numérique prédicteur-correcteur de Maccormack, implicite et volumes finis, est détaillée. L'exploitation et l'analyse des résultats numériques constituent le cinquième chapitre. Le dernier chapitre est consacré aux conclusions et perspectives
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Riveiro, Moreno Carmen. "Interaction of shock waves with compliant walls." Electronic Thesis or Diss., Institut polytechnique de Paris, 2024. http://www.theses.fr/2024IPPAX011.
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Cette thèse vise à caractériser l'interaction entre une paroi souple et un choc normal transsonique. La topologie et la dynamique de l'écoulement sur une paroi rigide sont d'abord déterminées. En utilisant visualisations strioscopiques et des mesures de pression instationnaires, les différentes échelles temporelles et de longueur impliquées dans l'interaction entre l'onde de choc et la couche limite turbulente sont caractérisées.Une paroi souple est ensuite conçue de manière à ce que ses fréquences naturelles se situent dans le même ordre de grandeur que la gamme de fréquences des oscillations des ondes de choc. De cette manière, la paroi retenue pour l'étude est censée réagir au forçage de l'onde de choc. Le matériau et la géométrie de la paroi souple sont déterminés par des études numériques paramétriques basées sur l'analyse modale ainsi que sur la déformation statique de la paroi souple causée par l'écoulement. Deux parois conformes sont fabriquées, l'une présentant un comportement élastique et l'autre un comportement viscoélastique.L'interaction entre l'onde de choc normale et les parois conformes est caractérisée expérimentalement. Dans les deux cas, plusieurs positions de choc dans la veine d'essais sont étudiées. Dans la configuration de la paroi souple élastique, l'interaction fluide-structure dépend fortement de la position du choc. L'interaction fluide-structure varie d'un régime synchrone de grande amplitude à un régime non synchronisé, en fonction de la position du choc. Le régime synchrone à grande amplitude a été étudié en fonction des fréquences naturelles de la structure. À cette fin, l'épaisseur de la paroi souple et les conditions aux limites ont été modifiées. L'amplitude des oscillations diminue considérablement avec l'augmentation de l'épaisseur. La fixation de la surface inférieure de la paroi élastique n'entraîne aucune interaction fluide-structure. Dans la configuration de la paroi souple viscoélastique, on observe de grandes déformations de la paroi souple sans interaction dynamique fluide-structure. Ce résultat met en évidence la capacité des matériaux viscoélastiques à réagir différemment en fonction de la fréquence du forçage externe : la grande déformation statique de la paroi souple correspond à une structure souple, tandis que sa réponse dynamique est caractéristique d'une structure rigideThis thesis aims to characterize the interaction between a compliant wall and a transonic normal shock. The flow topology and dynamics over a rigid wall is first determined. Using schlieren visualisation and unsteady pressure measurements the different temporal and length scales involved in the shock wave turbulent boundary layer interaction are characterized.A compliant wall is then designed so that its natural frequencies are within the same order of magnitude as the frequency range of the shock oscillations. In that manner, the compliant wall is expected to react to the shock wave forcing. The compliant wall's material and geometry are determined through numerical parametric studies based on modal analysis as well as the static deformation of the compliant wall caused by the flow. Two compliant walls are manufactured, one exhibiting elastic behavior, and the other viscoelastic behavior.The interaction between the normal shock wave and the compliant walls are experimentally characterized. In both cases the shock location is varied. In the elastic compliant wall configuration, the fluid-structure interaction is highly dependent on the shock position. The fluid-structure interaction varies from a large-amplitude synchronized regime to a non-synchronized regime, depending on the shock position. The large-amplitude synchronized regime was studied as a function of the structural natural frequencies. For that purpose, the compliant wall thickness and boundary conditions were modified. With increasing thickness, the amplitude of the oscillations considerably diminishes. Clamping the bottom surface of the elastic compliant wall yields no fluid-structure interaction. On the viscoelastic compliant wall configuration, large deformations of the compliant wall with no dynamic fluid-structure interaction are found. Such a result highlights the capability of viscoelastic materials to react differently depending on the external forcing frequency: the compliant wall's large static deformation corresponds to a soft structure, whereas its dynamic response is characteristic of a rigid one
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Bardy, Simon. "Contrôle et optimisation du test d'adhérence par choc laser sur assemblages collés." Thesis, Paris, ENSAM, 2017. http://www.theses.fr/2017ENAM0061/document.
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La généralisation du procédé d’assemblage par collage au sein des structures aérospatiales, aéronautiques et automobiles est confrontée au besoin d’évaluation non destructive quantitative des assemblages. Le procédé de test d’adhérence par choc laser (LASAT) répond à cette problématique par la sollicitation calibrée des joints collés et l’utilisation de diagnostics non-destructifs pour déterminer l’état résiduel des joints suite à cette sollicitation qui doit décoller les joints faibles et préserver l’intégrité structurelle des assemblages corrects. La détermination des paramètres laser optimaux pour mettre en œuvre ce test d’épreuve non-destructif (ND-LASAT) est réalisée par l’application d’une méthodologie bien définie. Cette dernière implique la caractérisation par une approche expérimentale et numérique de l’assemblage considéré, suivie d’une phase d’optimisation. La diversification des configurations d’interaction-laser matière impliquées dans ces configurations optimisées nécessite de disposer d’outils numériques pour prédire les chargements appliqués aux joints collés. Dans cette étude, le développement et la validation de modèles intégrés dans un code multi-physique répond à ce besoin. Un effort particulier a été porté sur l’évaluation de la précision des chargements simulés. Enfin, la démonstration du procédé ND-LASAT sur trois différents assemblages collés a été réalisée, validant ainsi la méthodologie et la chaine numérique développées dans cette étudeBonding process generalization within aerospace, aeronautical and automotive structures faces the need of quantitative non-destructive evaluation of assemblies. Laser shock adhesion test (LASAT) meets this requirement by applying a calibrated stress to bonded joints and using non-destructive diagnostics to determine the post-shock state of the joint. The calibrated stress must disbond weak joints and keep correct assemblies intact. Optimal laser parameters determination aims at implementing this non-destructive proof test (ND-LASAT). It is achieved through application of a well-defined methodology, which implies the concerned assembly characterization by an experimental and numerical approach, followed by an optimization step. Optimization implies diversification of laser-matter configurations. Use of numerical tools for predicting loadings applied to bonded joints is then required. Models development within a multi-physics code is proposed and validated here to respond to this need. A significant effort has been made for evaluating models’ precision. Experimental demonstration of ND-LASAT process is achieved on three different bonded assemblies, and thus validating both methodology and numerical chain developed in this study
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LACASSIN, GERALD. "Etude d'une interaction tridimensionnelle onde de choc/couche limite turbulente en ecoulement supersonique." Paris 6, 1995. http://www.theses.fr/1995PA066131.
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Cette etude traite de l'interaction tridimensionnelle onde de choc/couche limite turbulente, qui est un phenomene d'un grand interet pratique pour les avions supersoniques. L'interaction est induite par une plaque plane a bord d'attaque arrondi, montee perpendiculairement a la paroi inferieure d'une soufflerie. Les champs de vitesses moyennes et turbulentes sont mesures dans des plans longitudinaux, a l'aide d'explorations par velocimetrie laser tridimensionnelle, completees par des releves de pression parietale, et par des visualisations de lignes de frottement. La structure de chocs en lambda et l'organisation tourbillonnaire de l'ecoulement decolle sont examinees. Les proprietes de la turbulence sont analysees, notamment en relation avec la structure du champ moyen. Le trainage des particules d'ensemencement est evalue au voisinage des chocs. Cette experience est simulee par un code de resolution des equations moyennees en temps de navier-stokes compressibles, associees a un modele de turbulence algebrique de longueur de melange. La methode numerique employee se caracterise par un schema explicite centre avec une approche volumes finis, en maillage structure. Nous analysons l'influence de la distribution de viscosite turbulente sur l'interaction, ainsi que l'independance du calcul vis a vis du maillage. La validite du modele de turbulence est discutee par une confrontation avec certains resultats experimentaux
Books on the topic "Interaction choc"
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J, Spencer R., and Chou I. M, eds. Fluid-mineral interactions: a tribute to H.P. Eugster. by R.J. Spencer and I. Ming Chou, editors. San Antonio: The Geochemical Society, 1990.
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Hope, Jack. Interactions 6: Jack Hope, Marian Small; Consultants Valeen Chow ... [et. al.] Consultante à l'édition française Lise Patenaude-Bourgeois. Montréal: Les Éditions de la Chenelière inc., 1996.
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Ontario. Esquisse de cours 12e année: Sciences de l'activité physique pse4u cours préuniversitaire. Vanier, Ont: CFORP, 2002.
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Ontario. Esquisse de cours 12e année: Technologie de l'information en affaires btx4e cours préemploi. Vanier, Ont: CFORP, 2002.
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Ontario. Esquisse de cours 12e année: Études informatiques ics4m cours préuniversitaire. Vanier, Ont: CFORP, 2002.
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Ontario. Esquisse de cours 12e année: Mathématiques de la technologie au collège mct4c cours précollégial. Vanier, Ont: CFORP, 2002.
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Ontario. Esquisse de cours 12e année: Sciences snc4m cours préuniversitaire. Vanier, Ont: CFORP, 2002.
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Ontario. Esquisse de cours 12e année: English eae4e cours préemploi. Vanier, Ont: CFORP, 2002.
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Ontario. Esquisse de cours 12e année: Le Canada et le monde: une analyse géographique cgw4u cours préuniversitaire. Vanier, Ont: CFORP, 2002.
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Ontario. Esquisse de cours 12e année: Environnement et gestion des ressources cgr4e cours préemploi. Vanier, Ont: CFORP, 2002.
Find full textBook chapters on the topic "Interaction choc"
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Panissod, Pierre, and Marc Drillon. "Magnetic Ordering due to Dipolar Interaction in Low Dimensional Materials." In Magnetism: Molecules to Materials, 233–70. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2003. http://dx.doi.org/10.1002/9783527620548.ch7c.
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Novoa, Juan J., Pilar Lafuente, Mercè Deumal, and Fernando Mota. "Theoretical Study of the Electronic Structure and Magnetic Interactions in Purely Organic Nitronyl Nitroxide Crystals." In Magnetism: Molecules to Materials, 65–117. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2003. http://dx.doi.org/10.1002/9783527620548.ch3c.
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Babl, Virginia, Ulrike Stöckl, Herbert Tschochner, Philipp Milkereit, and Joachim Griesenbeck. "Chromatin Endogenous Cleavage (ChEC) as a Method to Quantify Protein Interaction with Genomic DNA in Saccharomyces cerevisiae." In Methods in Molecular Biology, 219–32. New York, NY: Springer New York, 2015. http://dx.doi.org/10.1007/978-1-4939-2877-4_14.
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Saleh, Moustafa M., Jason P. Tourigny, and Gabriel E. Zentner. "Genome-Wide Profiling of Protein–DNA Interactions with Chromatin Endogenous Cleavage and High-Throughput Sequencing (ChEC-Seq )." In Methods in Molecular Biology, 289–303. New York, NY: Springer US, 2021. http://dx.doi.org/10.1007/978-1-0716-1597-3_16.
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Coppen, S. R., R. Newsam, A. J. Baines, A. T. Bull, and C. Caulcott. "The Nature and Effect of Cell-Cell Interactions between Recombinant CHO Cells Producing Human Interferon-Gamma." In Animal Cell Technology: Basic & Applied Aspects, 9–18. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-2044-9_2.
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PETITEAU, Jean-Christophe, Pierre BERTHELOT, Kevin BROCHARD, and Alexis BLOC. "Tenue des structures composites sous chargements hydrodynamiques sévères." In Interactions fluide-structure, 343–71. ISTE Group, 2022. http://dx.doi.org/10.51926/iste.9078.ch11.
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Ce chapitre expose quelques modélisations numériques, utilisables par les ingénieurs du secteur naval, développées pour des calculs d’interaction fluide/structure concernant des structures composites soumises à des chargements hydrodynamiques « sévères », comme ceux engendré par des impacts hydrodynamiques (ou slamming) ou des explosions sous-marines (ou « choc hydrodynamique »).
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Burtt, Edward H., W. Chow, and G. A. Babbitt. "Occurrence and demography of mites of tree swallow:, house wren:, and eastern bluebird nests." In Bird-Parasite Interactions, 93–103. Oxford University PressOxford, 1991. http://dx.doi.org/10.1093/oso/9780198577386.003.0006.
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Abstract Debate over the evolutionary determinants of avian clutch size has ignored the potential of nest-dwelling, parasitic arthropods to significantly reduce the reproductive success of birds (McKilligan 1987; this volume: Delannoy and Cruz, Chapter 5; Rogers et al., Chapter 7). Parasitic mites (Arthropoda, Arachnida, Acari) occur in bird nests (Hicks 1953, 1959, 1971, 1975; Wilson 1965; Philips and Dindal 1977, 1979; Welch 1977), especially nests sheltered from weather and nests built in cavities (Woodroffe 1953; Moss 1978; Chow et al. 1983). Such mites are known to feed on blood, which causes weight loss and mortality of nestlings (Moss and Camin 1970) and may cause desertion of whole broods (Moss 1966).
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Shim, Janet K., Jamie Suki Chang, and Leslie A. Dubbin. "Cultural Health Capital." In Understanding Health Inequalities and Justice. University of North Carolina Press, 2016. http://dx.doi.org/10.5149/northcarolina/9781469630359.003.0010.
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The 2010 Patient Protection and Affordable Care Act promulgated a number of fundamental changes to the United States health-care system. Less visible and controversial aspects included the creation of institutions and strategies to reduce health disparities and enhance the quality and patient-centeredness of health care. In this chapter, we offer the concept of cultural health capital (CHC) as a sociological intervention for analyzing these changes aimed at making health care more patient-centered, particularly for historically underserved populations. In particular, we use the notion of CHC to illustrate how patient-centered care is accomplished or undone through complex interpersonal and interactional work that is highly dependent on access to stratified cultural resources that both patients and providers bring to health-care interactions. In so doing, we aim to contest that racism in health care is the primary source of health inequalities. Instead we argue that patients’ and providers’ cultural assets and interactional styles—themselves the product of complex social, cultural, historical, political, and economic contexts—influence their abilities to communicate with and understand one another.
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LAPIDUS, L. I., and KUANG-CHAO CHOU. "INELASTIC FINAL-STATE INTERACTIONS AND NEAR-THRESHOLD SINGULARITIES." In Selected Papers of K C Chou, 100–105. WORLD SCIENTIFIC, 2009. http://dx.doi.org/10.1142/9789814280389_0025.
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CHOU, KUANG-CHAO, and V. MAEVSKII. "THE UNIVERSAL FERMI INTERACTION AND THE CAPTURE OF MUONS IN HYDROGEN." In Selected Papers of K C Chou, 42–43. WORLD SCIENTIFIC, 2009. http://dx.doi.org/10.1142/9789814280389_0011.
Full textConference papers on the topic "Interaction choc"
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Kisel’, Vladimir, Asan Torgoev, and Askat Zhumabaev. "Warriors’ burials of Sacae times in Chon-Alai." In Antiquities of East Europe, South Asia and South Siberia in the context of connections and interactions within the Eurasian cultural space (new data and concepts). Institute for the History of Material Culture Russian Academy of Sciences, 2019. http://dx.doi.org/10.31600/978-5-907053-34-2-264-265.
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Federici, A. B., C. De Romeuf, P. G. De Groot, P. M. Mannucci, B. Samor, R. Lombardi, P. D'Alessio, C. Mazurier, and J. J. Sixma. "INCREASED ADHESIVE PROPERTIES OF THE CARBOHYDRATE-MODIFIED VON WILLEBRAND FACTOR (CHO-VWF): CRITICAL ROLE OF THE MULTIMERIC STRUCTURE AND CORRELATION WITH PLATELET AGGREGATION." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644094.
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We have reexplored the role of the carbohydrate moiety (CHO) on the von Willebrand Factor (vWF) structure and function by critically evaluating its different purification steps and modifications in CHO content by specific enzymes. Structural and functional assays have been evaluated separately in each laboratory (Milano and Lille) and jointly in Utrecht during several organized experiments. Under our conditions, the CHOVWFs obtained were characterized by less than 5% of sialic acid "(Neu)asevWF" and about 45% of D-Galactose "(Neu-Gal)ase-vWF" remaining, by increased electrophoretic mobility without any significant losses of the high molecular weight multimers and by their capacity to induce spontaneous aggregation in normal platelet rich plasma (PRP). Platelet adhesion to these different CHO-vWFs was tested in the flat chamber devised by Sakariassen in the presence of different subendothelial matrices and data expressed as the percentage of the surface covered by platelets. The blood reconstituted with different plasma samples showed the following percentual values of surface coverage (mean ± SD):- Normal plasma = 15 ± 3.8- Severe vWd plasma = 4 ± 1.9- SvWd pl + Native vWF = 14 ± 2.8- SvWd pl + (Neu) ase-vWF = 23 ± 3.5- SvWd pl + (Neu-Gal) ase-vWF = 19 ± 2.9This significantly increased adhesion to the subendothelium of the CHO-vWFs corresponded to the spontaneous aggregation present in normal PRP but it disappeared when the multimeric structure was damaged by in vitro proteolysis and/or by storage conditions (changes in temperature and freezing and thawing). From these results we may conclude that removal of terminal sugars enhances not only platelet-vWF interactions, but also platelet adhesion to the subendothelium.
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Kim, Eunjung, Farshid Guilak, and Mansoor A. Haider. "Determination of In Situ Articular Cartilage Pericellular Matrix Properties via Inverse BEM Analysis of Chondron Deformation." In ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19308.
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The pericellular matrix (PCM) of articular cartilage is the narrow tissue region surrounding all chondrocytes. Together, the chondrocyte and its surrounding PCM have been termed the chondron. In normal cartilage, the presence of type VI collagen is exclusive to the PCM, and the PCM is believed to play a critical role in regulating biomechanical cell-matrix interactions. Since the PCM is stiffer than the chondrocyte, it has been hypothesized to play a critical role in protecting the cell while, simultaneously, facilitating the transmission of mechanical signals to the cell. Previous studies that represent the cell, PCM and extracellular matrix (ECM) as linear biphasic materials have supported this hypothesized role for the PCM [1–4]. Previous in vitro micropipette studies of isolated chondrons [5–7] have shown that the PCM Young’s modulus ranges between 25–70kPa in middle and deep zone cartilage, separating it by an order of magnitude from both the chondrocyte stiffness (∼1kPa) and ECM stiffness (∼1MPa). In recent years, Choi et al. [8] measured changes in the three-dimensional morphology of the chondron, in situ within the ECM, under equilibrium unconfined compression of porcine cartilage explants subjected to 10–50% compressive strain (Fig. 1). Their study employed a novel 3D confocal microscopy technique, based on immunolabeling of type VI collagen, that yielded ellipsoidal approximations of undeformed and deformed chondron shapes in the superficial, middle and deep zones of the explant. In this study, an efficient computational model, based on the boundary element method (BEM), was developed and used to estimate cartilage PCM linear elastic properties based on the data reported in Choi et al. [8] for the case of middle zone cartilage under 10% compressive strain.
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Qiu, Renyi, Guangqing Zhang, Zhong Anhai, Lu Mingjing, Yang Feng, and Dawei Zhou. "Effects of Supercritical CO2-Brine/shale Interaction on Fracturing Behavior." In 57th U.S. Rock Mechanics/Geomechanics Symposium. ARMA, 2023. http://dx.doi.org/10.56952/arma-2023-0607.
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ABSTRACT As a caprock for CO2 geological sequestration, the mechanical properties of shale may change significantly from the long-term CO2-fluid interaction. To study the long-term effects of supercritical CO2-brine interaction on the mechanical properties of shale, the marine LMX shale was treated with supercritical CO2-brine at temperature of 110 °C and pressure of 30 MPa for 15, 30, and 60 days, respectively. The Brazilian tests combined with Acoustic Emission (AE) monitoring were conducted on shale before and after the treatments. The results show that: (1) Compared with the dry shale, the tensile strength of shale saturated with supercritical CO2-brine for 15, 30, and 60 days decreases by 40%, 48.6%, and 68.8%, respectively. The fracture morphology changes from a straightly single fracture to a fracture band consisting of two to four curved fractures; (2) The effects of supercritical CO2-brine interaction on the initiation and damage stresses are quantitatively analyzed. Taking the initiation and damage stresses of dry shale as the reference, the initiation stresses of shale saturated with supercritical CO2-brine for 15, 30, and 60 days decrease by 17.7%, 37.8%, and 48.4%; the damage stresses decrease by 35.5%, 58.3%, and 75.8%; (3) The AE characteristics of shale are closely related to fracture modes. The tensile fracturing of shale is sudden, manifested as an obvious step in the cumulative AE energy, while the shear fracturing of shale is gradual. With the supercritical CO2-brine treatment time, the fracture mode gradually changes from tensile-dominated to tensile-shear mixed failure mode, which can be inferred from that the slight step increases significantly and the ratio of tensile to shear events decreases from 10.7:1 to 0.8:1. The mechanical properties of shale weaken with the increase of supercritical CO2-brine treatment time. INTRODUCTION As one of major greenhouse gases, excessive CO2 exacerbates global climate change. CO2 geological sequestration is one of the important means to mitigate the greenhouse effect by injecting large amounts of CO2 into deep formation (Bachu et al., 2007; Wood, 2015; Jia et al., 2019; Nie et al., 2022). The deep shale formation has low porosity, low permeability, with beddings, which can effectively prevent and isolate the upward migration and leakage of CO2, which is suitable for the target formation of CO2 geological sequestration (Kalantari-Dahaghi, 2010; Lyu et al., 2021; Xie and Economides, 2009; Liu et al., 2013; Chen et al., 2015; Chen et al., 2023; Zhang et al., 2021). CO2-shale-fluid interaction will significantly affect the mechanical properties of shale under the condition of high temperature and high pressure for long-term CO2 geological sequestration (Zou et al., 2018; Al-Ameri et al., 2016; Choi and Song, 2012; Zhou et al., 2022).
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Ballinger, Bradley, Brett Green, Pavan Vajjha, Jackson Haffener, Mark Edwards, Mouin Almasoodi, and Kyle Haustveit. "Understanding the Hydraulic and Conductive Half Lengths in the Bakken/Three Forks Play – Coupling Sealed Wellbore Pressure Monitoring SWPM & Chow Pressure Group CPG." In SPE Hydraulic Fracturing Technology Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/209144-ms.
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Abstract In development of the Bakken/Three Forks play, it is crucial to obtain a strong understanding of not just the hydraulic fracture geometry, but also what portion of those hydraulic fractures are conductive. If both parameters and their interactions are not fully understood, then development of the play could be severely compromised due to unoptimized well spacing and completion design. This study represents a two-pronged approach to better understand this interaction. The first step was to perform a Sealed Wellbore Pressure Monitoring (SWPM) test to gain an understanding of hydraulic half-length (Haustveit. et al. 2020). Then, a conductive interference test was performed to utilize Chow Pressure Group (CPG) to understand the conductive half-length (Chu et al. 2018). This paper will address the results from these two tests and how they can be coupled together to optimize the unique relationship between well spacing and completion design to maximize the value in development of the Bakken/Three Forks play or any play both new and mature. The SWPM test was successfully completed on a nine well zipper frac operation consisting of two pads (four well pad/five well pad) where four Middle Bakken and five Three Forks wells were stimulated. The SWPM results provided insight into the hydraulic fracture geometry of the stimulation in multiple scenarios of vertical and lateral separation, as well as various amounts of offsetting depletion. The next step in the analysis was performing a CPG interference test on the five well zipper pad. The CPG results provided insight into not just the initial conductive geometry, but a three month follow up test also showed how the conductivity of the fractures rapidly degrade over time. By coupling the SWPM and CPG analysis together, an operator can learn where hydraulic fractures are growing and what portion of those fractures are conductive. This project design of coupled SWPM and CPG provided multiple learnings: Hydraulic fractures for a well in either the Middle Bakken or Three Forks grow through the Lower Bakken Shale and create large geometries in both the landing and staggered zone Hydraulic growth is faster and geometry larger growing towards modern completion parents versus vintage completion parents A relatively small portion of the hydraulic geometry is conductive, and although early time wells communicate through the Lower Bakken Shale, a 3-month interference test shows closure between the Three Forks and Middle Bakken. From these learnings, an optimized development is being developed for the Bakken/Three Forks play and a similar workflow can be applied to any play both new or mature to maximize value and returns for operators.
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Zhang, Xinyue, Wei Wang, Xiaopeng Wang, Guanhua Sun, and Yikai Zhong. "High-Frequency Gripping Area for One-Handed Smartphone Rear Interactions." In 15th International Conference on Applied Human Factors and Ergonomics (AHFE 2024). AHFE International, 2024. http://dx.doi.org/10.54941/ahfe1004814.
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Recent years of cell phone development have proposed ways to extend the interaction with mobile devices by equipping the device with a touch-sensitive rear for back-of-device (BoD) interaction. Although previous work [1] provided a classification of hand-hold/grip styles, a detailed understanding of the location of high-frequency touch areas at the back of the cell phone and the position of different fingers is missing. Knowledge of this information is necessary to develop ergonomically based interaction techniques on the back of the device. In addition, the location of high-frequency gripping areas needs to be taken into account when designing the location and size of the heating elements of a cell phone, and such areas should be avoided as much as possible to achieve a better user experience. The purpose of this study is to investigate the distribution of high-frequency gripping areas in the portrait view (one-handed vertical screen scenarios) for BoD interaction of a cell phone. We conducted an experiment to collect the rear area of the phone held by one hand in the natural settings. The rear and surrounding bezel area of the phone is partitioned in 10*10mm squares, with a total of 8*16 grids. 60 human subjects (normal smartphone users recruited by demographic segments) participated in this study. Their hand-hold/grip behaviors data were recorded by simulating their natural usage of the testing device with using an ink-based handprint technique. Then, through image recognition, filter the grid of the rear and surrounding bezel area of the phone, where handprints area account for more than 40% of the grid area. The final processing of the experiment yields a high-frequency grip area map and its corresponding grip posture which indicates how the user hold the smartphone and their BoD interaction. The whole grip area can be divided into three major parts: purlicue area (space between the forefinger and thumb), index finger area, and three fingers (middle, ring, and pinky) area. The results show that in the purlicue area and three-finger area, the grip frequency is normally distributed, and the location and size of the specific areas where the users' grip frequency reaches 90% and 95% in these two areas are obtained. The high-frequency grasping area identified in this study could provide references to design BoD interaction and improve the touch experience on the rear of such devices. In addition, the research results can lay the foundation for exploring the thermal tactile experience of mobile devices, provide a theoretical basis for the PCB layout design of heating components in mobile phones, and guide the system optimization of mobile phone cooling systems.Reference:[1]Choi, Y., Jung, H., Park, J., & You, H. (2017, September). Analysis of grip posture for ergonomic smartphone interface design. In Proceedings of the Human Factors and Ergonomics Society Annual Meeting (Vol. 61, No. 1, pp. 1058-1061). Sage CA: Los Angeles, CA: SAGE Publications.
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Choi-Rokas, Hyegjoo, Todd Garlie, and K. Blake Mitchell. "Theoretical Framework for the Sizing of Body Armor Plates to Optimize Fit." In 13th International Conference on Applied Human Factors and Ergonomics (AHFE 2022). AHFE International, 2022. http://dx.doi.org/10.54941/ahfe1001898.
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The development of optimized fitting body armor is critical to the fightability and protection of our warfighters and first responders. Body armor systems generally worn by warfighters consists of three protective portions: rigid plates, a soft armor insert, and a carrier/vest. Rigid plates are inserted into the front, back, and sides of the body armor to provide a higher level of protection for the wearer, while the soft armor is positioned behind the plates and in areas of the body where a lower level of protection is acceptable or required for mobility and comfort. Previously, a comprehensive fit mapping study on the family of armor plates to investigate the relationship between the coverage, anthropometry and mobility relative to size specifications of torso and side plates was conducted (Choi et. al., 2017). There is a delicate tradeoff between covering more (i.e., a greater area of protection) while not degrading the wearer’s mission performance (primarily their mobility). However, some level of mobility degradation is unavoidable. Choi et. al. (2017)'s results quantitatively defined the impact of coverage on mobility, visualized the mobility degradation as coverage increase, and set the allowable mobility degradation to be 10%. The coverage corresponding to the allowable mobility degradation was then converted into anthropometric dimensions. Accommodation envelopes for the current U.S. Army torso plates, relative to the male and female US Army population, were reported. Final size tariffs were calculated using the front plate. A sizing system for the back plate and/or side plates were not developed.This current study explores a theoretical framework for ballistic rigid plate size optimization for the front, back and side plates. When the protection coverage is maximized with minimal mobility degradation, the system would be considered optimized. For this study, minimal mobility degradation was set to 10%. For the front plate, Choi et. al. was revisited to retrieve the maximum width and length while limiting the mobility degradation to 10%. Chest Breadth, was measured using the ANSUR II (Gordon et. al., 2014) procedure, and Suprasternale -Tenth Rib Length was used to derive the width and length of plates, respectively. Then, a specification of the front ballistic plate, given anthropometric characteristics of the current U.S. Army population was developed from a reverse engineering approach. Theoretical accommodation envelopes for each front plate size were then developed and plotted against the current ANSUR II data. Once the front plate sizing system was developed, anthropometric characteristics of cases within each accommodation envelope per size were investigated to develop the required size specifications for the back plate. The width of the back plate shares the width of the matching front plate, but the length takes into account the back length, from the Cervicale -Tenth Rib Length. Size specifications for the side plates were also developed. Given that the front and back plates are worn together; the maximum width of the side plate is defined by the surface availability at the location of the tenth rib level. The side plate length is defined using the distance between Tenth Rib and the Axilla. A theoretical size system for a family of rigid armor plates is presented in a series of tables as well as bivariate plots. A detailed process for plate size prediction and the interaction between the front, back and side plates is presented.
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Graham, Owen S., and Ann P. Dowling. "A Low-Order Modelling of Ducted Flames With Temporally Varying Equivalence Ratio in Realistic Geometries." In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-45255.
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The interaction between unsteady heat release and acoustic pressure oscillations in gas turbines results in self-excited combustion oscillations which can potentially be strong enough to cause significant structural damage to the combustor. Correctly predicting the interaction of these processes, and anticipating the onset of these oscillations can be difficult. In recent years much research effort has focused on the response of premixed flames to velocity and equivalence ratio perturbations. In this paper, we develop a flame model based on the so-called G-Equation, which captures the kinematic evolution of the flame surfaces, under the assumptions of axisymmetry, and ignoring vorticity and compressibility. This builds on previous work by Dowling [1], Schuller et al. [2], Cho & Lieuwen [3], among many others, and extends the model to a realistic geometry, with two intersecting flame surfaces within a non-uniform velocity field. The inputs to the model are the free-stream velocity perturbations, and the associated equivalence ratio perturbations. The model also proposes a time-delay calculation wherein the time delay for the fuel convection varies both spatially and temporally. The flame response from this model was compared with experiments conducted by Balachandran [4, 5], and found to show promising agreement with experimental forced case. To address the primary industrial interest of predicting self-excited limit cycles, the model has then been linked with an acoustic network model to simulate the closed-loop interaction between the combustion and acoustic processes. This has been done both linearly and nonlinearly. The nonlinear analysis is achieved by applying a describing function analysis in the frequency domain to predict the limit cycle, and also through a time domain simulation. In the latter case, the acoustic field is assumed to remain linear, with the nonlinearity in the response of the combustion to flow and equivalence ratio perturbations. A transfer function from unsteady heat release to unsteady pressure is obtained from a linear acoustic network model, and the corresponding Green function is used to provide the input to the flame model as it evolves in the time domain. The predicted unstable frequency and limit cycle are in good agreement with experiment, demonstrating the potential of this approach to predict instabilities, and as a test bench for developing control strategies.
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Khmelovskyi, Vasyl, Roman Vasylenko, Victor Rebenko, and Svitlana Potapova. "Intensification of stem material shredding process." In 23rd International Scientific Conference Engineering for Rural Development. Latvia University of Life Sciences and Technologies, Faculty of Engineering and Information Technologies, 2024. http://dx.doi.org/10.22616/erdev.2024.23.tf088.
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At the current stage of technology development, roughage shredding is carried out mainly by mechanical means, which ensures high reliability and is characterized by the simplicity of the design of working bodies. The main issues of our work are to improve the process of shredding roughage by changing the design of the chopper and optimizing its parameters, which will ensure shredding of roughage with minimal specific energy and metal consumption. To conduct the research, a two-stage chopper design was proposed, and a pilot plant was manufactured, which has the ability to chop long-fiber feed materials and separate them along the fibers with breakage of stem nodes. The operating range of the rotor speed was in the range of 500-700 rpm, and the gap between the movable and fixed pins 0.015-0.025 m. The nature of the interaction of a particle of roughage, after cutting the layer with a curved knife, with the wing and the pin during the splitting of the stem along the fibers was determined. It was found that with a decrease in the rotor speed, the material moving to the pins does not reach absolute speed, which ensures the creation of an impact that should be sufficient to destroy the stem. In addition, a rotor speed of less than 500 rpm does not allow for the creation of an air flow that ensures the removal of feed components from the splitting zone, thereby limiting the chopper throughput. Increasing the rotation speed above 900 rpm leads to an increase in energy performance and reduces the percentage of split stalks of roughage.
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Schwarz, Benjamin, Mourad Zoubir, Jan Heidinger, Marthe Gruner, Hans-christian Jetter, and Thomas Franke. "Investigating Challenges in Decision Support Systems for Energy-Efficient Ship Operation: A Transdisciplinary Design Research Approach." In AHFE 2023 Hawaii Edition. AHFE International, 2023. http://dx.doi.org/10.54941/ahfe1004281.
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To increase energy-efficiency and reduce CO2e emissions in maritime shipping, Decision-Support Systems (DSS) can be leveraged. Specifically, in regard to reducing the greatest contributor to consumption, propulsion (IMO, 2021), by assisting seafarers in route planning, and timely and efficient re-planning, as well as general monitoring of ship’s energy dynamics. However, the successful integration and acceptance of these systems into the seafarer’s workflow pose significant challenges, such as goal conflicts, e.g. with safety or with the financial interests of different stakeholders, which require a deep understanding of interactions onboard and onshore.This paper reflects on our implementation of a transdisciplinary design research approach for developing novel, human-centered AI-based tools for energy-efficient ship operations. Of our concurrent studies, we describe selected forms of inquiry that together resulted in a holistic understanding of the application domain, target audience, and typical tasks as well as an interactive prototype of a decision support system for energy-efficient ship navigation.The research activities reported are based on human factors research concerning energy-efficient ship operations and focus on research through design in the sense of Jonas (2015) in the field of DSS for CO2e emission mitigation in navigation and ship operation, and the formative evaluation of a DSS prototype in a ship simulator environment (N = 22). By viewing these research activities through the lens of design research, more specifically the theoretical foundation of MAPS (Jonas et al., 2010), we systematically describe and discuss their individual contributions. MAPS specifically operationalized design research as “Matching Analysis, Projection and Synthesis”, enabling integrative, systematic research processes across boundaries of disciplinary bodies of knowledge, domains and actors.As a primary contribution, we reflect on our lessons learned to identify generalizable challenges for similar future projects of the maritime ergonomics community. These include (1) context-sensitive integration of navigational and operational data; (2) calibration of users’ expectations of the system’s capabilities; and related to this (3) increasing transparency of how the DSS retrieves and processes data, and of how confident it is in its suggestions. By considering key human factors, such as workload, autonomy and biases (e.g., automation bias) on the basis of our system, we demonstrate how these challenges can be addressed. As a secondary contribution, we also share our resulting designs as examples of how AI-based decision support for optimizing energy efficiency can be visually and functionally integrated into onboard ship operation and navigation.REFERENCESIMO, 2021. Fourth IMO GHG Study 2020. International Maritime Organization, London, UK.Jonas, W., 2015. Research through design is more than just a new form of disseminating design outcomes. Constructivist Foundations 11, 32–36.Jonas, W., Chow, R., Bredies, K., Vent, K., 2010. Far beyond dualisms in methodology – an integrative design research medium “MAPS.”
Reports on the topic "Interaction choc"
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Smalley, A. J., and P. J. Pantermuehl. TR-97-3 Friction Tests Typical Chock Materials and Cast Iron. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), December 1997. http://dx.doi.org/10.55274/r0011982.
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ADAS, RSK. Nitrate Surveillance Monitoring Program (Annual Report May 2021 - March 2022). Food Standards Agency, December 2022. http://dx.doi.org/10.46756/sci.fsa.uau489.
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Every Member State is required to monitor and report levels of nitrate in specified foodstuffs as part of the European Commission regulation and the UK also requires this information as part of the collection of data to support the review of retained EU law in the UK and inform the setting of policy around maximum nitrate levels. The requirement to carry out monitoring for nitrate in lettuce, spinach and rocket is being met by the UK Nitrate Surveillance Programme. Results are presented for the period between 1st April 2021 and 31st March 2022. A total of 202 samples were collected within the sampling period, comprising of 130 lettuce, 9 rocket, 26 spinach samples. A further 37 samples categorised at “Other Green Leafy Vegetables”, which comprised of samples including mustard, mizuna, celery, Pak Choi and cabbage. The lowest average nitrate concentration was recorded in summer-grown iceberg lettuce (935.2 mg/kg), and no iceberg samples exceeded the maximum nitrate concentration. The highest average nitrate concentration was seen in winter grown non-iceberg lettuce grown under protection within the lettuce group (3242.2 mg/kg), and in winter-grown rocket overall (4271.2 mg/kg). The number of samples exceeding the maximum threshold increased this year to 7 samples – 2 samples of open-air non-iceberg lettuce sampled in the summer, 1 sample of protected non-iceberg lettuce in the summer, and 3 samples of spinach. A further 4 samples were within 10% of the maximum threshold. Consistent with previous years of this project, a strong correlation was found between nitrate concentration and sampling date, with samples collected later in the season showing greater concentrations, indicating potential interactions between nitrate accumulation and climate – particularly light levels and available soil moisture and the accumulation of nitrate in the soil through subsequent fertiliser applications with successive planting. Furthermore, there was significant interaction between nitrate accumulation, product type and cultivation type, which could be further explored to better identify risk factors associated with nitrate accumulation in leafy vegetables grown in the UK.
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Wang, X. F., and M. Schuldiner. Systems biology approaches to dissect virus-host interactions to develop crops with broad-spectrum virus resistance. Israel: United States-Israel Binational Agricultural Research and Development Fund, 2020. http://dx.doi.org/10.32747/2020.8134163.bard.
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More than 60% of plant viruses are positive-strand RNA viruses that cause billion-dollar losses annually and pose a major threat to stable agricultural production, including cucumber mosaic virus (CMV) that infects numerous vegetables and ornamental trees. A highly conserved feature among these viruses is that they form viral replication complexes (VRCs) to multiply their genomes by hijacking host proteins and remodeling host intracellular membranes. As a conserved and indispensable process, VRC assembly also represents an excellent target for the development of antiviral strategies that can be used to control a wide-range of viruses. Using CMV and a model virus, brome mosaic virus (BMV), and relying on genomic tools and tailor-made large-scale resources specific for the project, our original objectives were to: 1) Identify host proteins that are required for viral replication complex assembly. 2) Dissect host requirements that determine viral host range. 3) Provide proof-of-concept evidence of a viral control strategy by blocking the viral replication complex-localized phospholipid synthesis. We expect to provide new ways and new concepts to control multiple viruses by targeting a conserved feature among positive-strand RNA viruses based on our results. Our work is going according to the expected timeline and we are progressing well on all aims. For Objective 1, among ~6,000 yeast genes, we have identified 96 hits that were possibly play critical roles in viral replication. These hits are involved in cellular pathways of 1) Phospholipid synthesis; 2) Membrane-shaping; 3) Sterol synthesis and transport; 4) Protein transport; 5) Protein modification, among many others. We are pursuing several genes involved in lipid metabolism and transport because cellular membranes are primarily composed of lipids and lipid compositional changes affect VRC formation and functions. For Objective 2, we have found that CPR5 proteins from monocotyledon plants promoted BMV replication while those from dicotyledon plants inhibited it, providing direct evidence that CPR5 protein determines the host range of BMV. We are currently examining the mechanisms by which dicot CPR5 genes inhibit BMV replication and expressing the dicot CPR5 genes in monocot plants to control BMV infection. For Objective 3, we have demonstrated that substitutions in a host gene involved in lipid synthesis, CHO2, prevented the VRC formation by directing BMV replication protein 1a (BMV 1a), which remodels the nuclear membrane to form VRCs, away from the nuclear membrane, and thus, no VRCs were formed. This has been reported in Journal of Biological Chemistry. Based on the results from Objective 3, we have extended our plan to demonstrate that an amphipathic alpha-helix in BMV 1a is necessary and sufficient to target BMV 1a to the nuclear membrane. We further found that the counterparts of the BMV 1a helix from a group of viruses in the alphavirus-like superfamily, such as CMV, hepatitis E virus, and Rubella virus, are sufficient to target VRCs to the designated membranes, revealing a conserved feature among the superfamily. A joint manuscript describing these exciting results and authored by the two labs will be submitted shortly. We have also successfully set up systems in tomato plants: 1) to efficiently knock down gene expression via virus-induced gene silencing so we could test effects of lacking a host gene(s) on CMV replication; 2) to overexpress any gene transiently from a mild virus (potato virus X) so we could test effects of the overexpressed gene(s) on CMV replication. In summary, we have made promising progress in all three Objectives. We have identified multiple new host proteins that are involved in VRC formation and may serve as good targets to develop antiviral strategies; have confirmed that CPR5 from dicot plants inhibited viral infection and are generating BMV-resistance rice and wheat crops by overexpressing dicot CPR5 genes; have demonstrated to block viral replication by preventing viral replication protein from targeting to the designated organelle membranes for the VRC formation and this concept can be further employed for virus control. We are grateful to BARD funding and are excited to carry on this project in collaboration.
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Chen, Junping, Zach Adam, and Arie Admon. The Role of FtsH11 Protease in Chloroplast Biogenesis and Maintenance at Elevated Temperatures in Model and Crop Plants. United States Department of Agriculture, May 2013. http://dx.doi.org/10.32747/2013.7699845.bard.
Full textAbstract:
specific objectives of this proposal were to: 1) determine the location, topology, and oligomerization of FtsH11 protease; 2) identify the substrate/s of FtsH11 and the downstream components involved in maintaining thermostability of chloroplasts; 3) identify new elements involved in FtsH11 protease regulatory network related to HT adaptation processes in chloroplast; 4) Study the role of FtsH11 homologs from crop species in HT tolerance. Background to the topic: HT-tolerant varieties that maintain high photosynthetic efficiency at HT, and cope better with daily and seasonal temperature fluctuations are in great need to alleviate the effect of global warming on food production. Photosynthesis is a very complex process requiring accurate coordination of many complex systems and constant adjustments to the changing environments. Proteolytic activities mediated by various proteases in chloroplast are essential part of this process and critical for maintaining normal chloroplast functions under HT. However, little is known about mechanisms that contribute to adaptation of photosynthetic processes to HT. Our study has shown that a chloroplast-targeted Arabidopsis FtsH11 protease plays an essential and specific role in maintaining thermostability of thylakoids and normal photosynthesis at moderate HT. We hypothesized that FtsH11 homologs recently identified in other plant species might have roles similarly to that of AtFtsH1. Thus, dissecting the underlying mechanisms of FtsH11 in the adaptation mechanisms in chloroplasts to HT stress and other elements involved will aid our effort to produce more agricultural products in less favorable environments. Major conclusions, solutions, achievements - Identified the chloroplast inner envelope membrane localization of FtsH11. - Revealed a specific association of FtsH11 with the a and b subunits of CPN60. - Identified the involvement of ARC6, a protein coordinates chloroplast division machineries in plants, in FtsH11 mediated HT adaptation process in chloroplast. -Reveal possible association of a polyribonucleotide nucleotidyltransferase (cpPNPase), coded by At3G03710, with FtsH11 mediated HT adaptation process in chloroplast. - Mapped 4 additional loci in FtsH11 mediated HT adaptation network in chloroplast. - Demonstrated importance of the proteolytic activity of FtsH11 for thermotolerance, in addition to the ATPase activity. - Demonstrated a conserved role of plant FtsH11 proteases in chloroplast biogenesis and in maintaining structural and functional thermostability of chloroplast at elevated temperatures. Implications, both scientific and agricultural:Three different components interacting with FtsH11 were identified during the course of this study. At present, it is not known whether these proteins are directly involved in FtsH11mediated thermotolerance network in chloroplast and/or how these elements are interrelated. Studies aiming to connect the dot among biological functions of these networks are underway in both labs. Nevertheless, in bacteria where it was first studied, FtsH functions in heat shock response by regulating transcription level of σ32, a heat chock factor regulates HSPsexpression. FtsH also involves in control of biosynthesis of membrane components and quality control of membrane proteins etc. In plants, both Arc 6 and CPN60 identified in this study are essential in chloroplast division and developments as mutation of either one impairs chloroplast division in Arabidopsis. The facts that we have found the specific association of both α and β CPN60 with FtsH11 protein biochemically, the suppression/ enhancement of ftsh11 thermosensitive phenotype by arc6 /pnp allele genetically, implicate inter-connection of these networks via FtsH11 mediated network(s) in regulating the dynamic adaptation processes of chloroplast to temperature increases at transcriptional, translational and post-translational levels. The conserved role of FtsH11 proteases in maintaining thermostability of chloroplast at HT demonstrated here provides a foundation for improving crop photosynthetic performance at high temperatures.