Bibliografie tematiche / Boundary triples

Letteratura scientifica selezionata sul tema "Boundary triples"

Autore: Grafiati

Pubblicato: 8 giugno 2024

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Articoli di riviste sul tema "Boundary triples":

Behrndt, Jussi, e Till Micheler. "Boundary triples and quasi boundary triples for elliptic operators". PAMM 11, n. 1 (dicembre 2011): 883–84. http://dx.doi.org/10.1002/pamm.201110428.

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Strelnikov, D. I. "Boundary triples for integral systems". Reports of the National Academy of Sciences of Ukraine, n. 7 (24 luglio 2018): 3–9. http://dx.doi.org/10.15407/dopovidi2018.07.003.

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Post, O. "First-order operators and boundary triples". Russian Journal of Mathematical Physics 14, n. 4 (dicembre 2007): 482–92. http://dx.doi.org/10.1134/s1061920807040139.

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Iochum, B., e C. Levy. "Spectral triples and manifolds with boundary". Journal of Functional Analysis 260, n. 1 (gennaio 2011): 117–34. http://dx.doi.org/10.1016/j.jfa.2010.09.006.

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Brown, B. M., M. Marletta, S. Naboko e I. Wood. "Inverse problems for boundary triples with applications". Studia Mathematica 237, n. 3 (2017): 241–75. http://dx.doi.org/10.4064/sm8613-11-2016.

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Hayashi, Toshinori, Alessandro A. Trani e Yasushi Suto. "Dynamical Disruption Timescales and Chaotic Behavior of Hierarchical Triple Systems". Astrophysical Journal 939, n. 2 (1 novembre 2022): 81. http://dx.doi.org/10.3847/1538-4357/ac8f48.

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Abstract We examine the stability of hierarchical triple systems using direct N-body simulations without adopting a secular perturbation assumption. We estimate their disruption timescales in addition to the mere stable/unstable criterion, with particular attention to the mutual inclination between the inner and outer orbits. First, we improve the fit to the dynamical stability criterion by Mardling & Aarseth widely adopted in the previous literature. Especially, we find that that the stability boundary is very sensitive to the mutual inclination; coplanar retrograde triples and orthogonal triples are much more stable and unstable, respectively, than coplanar prograde triples. Next, we estimate the disruption timescales of triples satisfying the stability condition up to 109 times the inner orbital period. The timescales follow the scaling predicted by Mushkin & Katz, especially at high e out where their random walk model is most valid. We obtain an improved empirical fit to the disruption timescales, which indicates that the coplanar retrograde triples are significantly more stable than the previous prediction. We furthermore find that the dependence on the mutual inclination can be explained by the energy transfer model based on a parabolic encounter approximation. We also show that the disruption timescales of triples are highly sensitive to tiny changes of the initial parameters, reflecting the genuine chaotic nature of the dynamics of those systems.

Strelnikov, Dmytro. "Boundary triples for integral systems on finite intervals". Journal of Mathematical Sciences 231, n. 1 (18 aprile 2018): 83–100. http://dx.doi.org/10.1007/s10958-018-3807-z.

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Behrndt, Jussi, Matthias Langer, Vladimir Lotoreichik e Jonathan Rohleder. "Quasi boundary triples and semi-bounded self-adjoint extensions". Proceedings of the Royal Society of Edinburgh: Section A Mathematics 147, n. 5 (28 giugno 2017): 895–916. http://dx.doi.org/10.1017/s0308210516000421.

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In this note semi-bounded self-adjoint extensions of symmetric operators are investigated with the help of the abstract notion of quasi boundary triples and their Weyl functions. The main purpose is to provide new sufficient conditions on the parameters in the boundary space to induce self-adjoint realizations, and to relate the decay of the Weyl function to estimates on the lower bound of the spectrum. The abstract results are illustrated with uniformly elliptic second-order partial differential equations on domains with non-compact boundaries.

Storozh, O. G. "On an approach to the construction of the Friedrichs and Neumann-Krein extensions of nonnegative linear relations". Carpathian Mathematical Publications 10, n. 2 (31 dicembre 2018): 387–94. http://dx.doi.org/10.15330/cmp.10.2.387-394.

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Let $L_{0}$ be a closed linear nonnegative (probably, positively defined) relation ("multivalued operator") in a complex Hilbert space $H$. In terms of the so called boundary value spaces (boundary triples) and corresponding Weyl functions and Kochubei-Strauss characteristic ones, the Friedrichs (hard) and Neumann-Krein (soft) extensions of $L_{0}$ are constructed. It should be noted that every nonnegative linear relation $L_{0}$ in a Hilbert space $H$ has two extremal nonnegative selfadjoint extensions: the Friedrichs extension $L_{F}$ and the Neumann-Krein extension $L_{K},$ satisfying the following property: $$(\forall \varepsilon > 0) (L_{F} + \varepsilon 1)^{-1} \leq (\widetilde{L} + \varepsilon 1)^{-1} \leq (L_{K} + \varepsilon 1)^{-1}$$ in the set of all nonnegative selfadjoint subspace extensions $\widetilde{L}$ of $L_{0}.$ The boundary triple approach to the extension theory was initiated by F.S. Rofe-Beketov, M.L. and V.I. Gorbachuk, A.N. Kochubei, V.A. Mikhailets, V.O. Dercach, M.N. Malamud, Yu. M. Arlinskii and other mathematicians. In addition, it is showed that the construction of the mentioned extensions may be realized in a more simple way under the assumption that initial relation is a positively defined one.

BRÜNING, JOCHEN, VLADIMIR GEYLER e KONSTANTIN PANKRASHKIN. "SPECTRA OF SELF-ADJOINT EXTENSIONS AND APPLICATIONS TO SOLVABLE SCHRÖDINGER OPERATORS". Reviews in Mathematical Physics 20, n. 01 (febbraio 2008): 1–70. http://dx.doi.org/10.1142/s0129055x08003249.

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We give a self-contained presentation of the theory of self-adjoint extensions using the technique of boundary triples. A description of the spectra of self-adjoint extensions in terms of the corresponding Krein maps (Weyl functions) is given. Applications include quantum graphs, point interactions, hybrid spaces and singular perturbations.

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Tesi sul tema "Boundary triples":

Siv, Easeng. "Étude expérimentale mésoscopique de la migration des interfaces dans le cuivre polycristallin". Thesis, Sorbonne Paris Cité, 2019. http://www.theses.fr/2019USPCD031.

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Un polycristal est constitué par un agglomérat de monocristaux micrométriques accolés les uns aux autres. L’interface entre deux monocristaux tournés constitue un joint de grains (JdG). Les JdGs jouent un rôle important dans le comportement plastique des matériaux cristallins. Sous certaines conditions de traitement thermique (TT) ou de thermomécanique (TM), les JdGs peuvent migrer et font évoluer profondément les microstructures. Ces phénomènes anciens restent toutefois mal connus et il n’existe pas de modèle quantitatif décrivant la migration. Dans ce contexte, nous avons étudié expérimentalement la migration des JdGs dans deux nuances de cuivre électrolytique de même pureté. L’un livré sous la forme d’une tôle obtenue par le laminage à froid suivi d’un recuit continu à 700°C (que l’on nommera cuivre I), est recristallisé. L’autre, fourni sous forme de cylindre (cuivre II) est partiellement recristallisé. Un traitement thermique initial permet d’obtenir un état de référence puis différents TT et TM sont effectués afin d’étudier la migration des joints.Nous recherchons les conditions de l’écrouissage critique (croissance de grains lors de recuit sans germination après très faible déformation plastique) afin d’observer la migration induite par déformation (Strain Induced Boundary Migration SIBM). Le déplacement de JdG par ce mécanisme a été observé in-situ sous le MEB. Une technique de mesure combinée EBSD et AFM est utilisé pour suivre de manière quantitative les évolutions microstructurales et évaluer les différentes forces motrices en présence. Le déplacement des JdGs est quantifié précisément grâce aux phénomènes de gravure thermique et l’existence de points fixes dans les clichées EBSD. L’énergie stockée, associée aux microstructures de dislocations dans chaque grain a été estimée par deux méthodes, la mesure de la désorientation locale à l’aide de cartographie de KAM et la simulation par modèle de Taylor relâché incluant un modèle de plasticité cristalline justifié physiquement et incluant une restauration isotrope ou anisotrope. La courbure des JdGs, 2nde force motrice en présence, est évaluée à partir des contours des JdGs expérimentaux. Un diagramme de migration a été tracé en fonction des déplacements de JdGs liant à l’énergie de courbure de JdG et à la différence d’énergie stockée. Il ressort des différences significative avec le comportement du polycristal d’Al, notamment liées à la différence d’énergie de faute d’empilement et l’existence de nombreuse macles. Le joint triple semble fortement influer le déplacement des JdGs qui a été étudié statistiquement pour le cuivre I à l’aide de donnée EBSD
A polycrystal is made up of an agglomerate of micrometric single crystals adjoining each other. The interface between two rotated single crystals forms a grain boundary (GB). GBs play an important role in the plastic behaviour of crystalline materials. Under certain conditions of heat (HT) or thermomechanical (TT) treatments, GBs can migrate and cause microstructures to evolve radically. However, these ancient phenomena remain poorly understood and there is no quantitative model describing migration. In this context, we experimentally studied the migration of GB in two grades of electrolytic copper of the same purity. One is delivered in the form of a sheet obtained by cold rolling followed by continuous annealing at 700°C (called copper I), and is recrystallized. The other, supplied as a cylinder (copper II), is partially recrystallized. An initial heat treatment allows to obtain a reference state then different HT and TM are carried out in order to study the migration of the grains boundaries.Our interest lies in the conditions of critical strain hardening (grain growth during germination-free annealing after very low plastic deformation) in order to observe strain-induced migration (Strain Induced Boundary Migration SIBM). The displacement of GB by the mechanism was observed in-situ in SEM. A combined EBSD and AFM measurement technique is used to quantitatively monitor microstructural changes and evaluate the different driving forces involved. The displacement of the GB is precisely quantified thanks to the phenomenon of thermal etching and the existence of stationary points in the EBSD pictures. The stored energy, associated with the dislocation microstructures in each grain, was estimated by two methods, the measurement of local disorientation using KAM mapping and the simulation by a relaxed Taylor model including a physically justified crystal plasticity law and accounting for an isotropic or anisotropic restoration. The curvature of GBs, the 2nd driving force involved, is evaluated from the observed contours of GBs. A migration diagram is drawn and represents the displacements of GBs as a function of estimates of the curvature energy of GB and the difference in stored energy. Significant differences with the behavior of Al polycrystals are noted, certainly due to the difference in stacking fault energy and the existence of numerous twins. From our statistical analysis of copper I using EBSD data, triple junctions seem to strongly influence the migration of GBs

Watkins, John D. "Enhancing triple phase boundary electrosynthesis". Thesis, University of Bath, 2011. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.547876.

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The first part of this thesis is concerned with the synthesis, characterisation and applications of surface functionalised carbon nanoparticles. Synthetic techniques are used to modify the existing surface architecture of carbon nanoparticles towards high surface area modified electrodes and pH sensing applications. Electrochemical and synthetic techniques have been used to study triple phase boundaries and enhance their properties towards a bulk synthetic technique, in which an electrolyte phase and redox probe phase are held separate. A salt matrix, ultrasound, high shear force and a carbon fibre membrane have all been used to form unique triple phase boundary environments in which electron and ion transfer processes can be studied and enhanced towards analytical and electrosynthetic applications. A number of electro-reduction reactions have been shown to be feasible using the triple phase boundary methodology. Alkenes, aldehydes and imines have all been successfully electro-reduced, analysed and optimised to elucidate the synthetic triple phase boundary mechanism.

Clarke, D. S. "Problems in triple-deck boundary layer theory". Thesis, University of Manchester, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370406.

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Collins, Andrew. "Photo-electrochemical processes at the triple phase boundary". Thesis, University of Bath, 2012. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.557818.

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The main aim and ultimate final goal of the work carried out in this thesis is a drive towards a feasible system for light harvesting, which is in short, using the Sun’s energy to create electricity or a fuel for our energy requirements here on Earth. This work will see an approach using the triple phase boundary afforded by a microdroplet array. Although light harvesting is an ambition which has seen decades of work and uncountable man-hours, approaching it from the angle of utilizing the triple phase boundary between two immiscible liquids and a solid electrode is a new, and novel concept. Before any attempts towards a light harvesting technique can be made, we will need to have characterized and fully understood the mechanisms and nuances, both for dark and light processes, that are observed at the triple phase boundary. This initial process will start by selection of a suitable redox molecule, and exploring its reactivity in microdroplets under dark conditions. Once this has been achieved, an attempt can be made to use this knowledge, and implement it towards light harvesting. This will eventually include an attempt to couple photo-excited states with other molecules, this will be an important step if energy is ever able to be stored from such a system. This early phase will also see the need to employ many other techniques other than electrochemistry in an effort to aid in the understanding and characterization of the triple phase boundary at microdroplets. This will include travelling to other laboratories in search of specialized scientific skills and apparatus, such as electron paramagnetic resonance, or photocurrent spectroscopy. It will also see the need to build new equipment needed to conduct tests such as surface tension visualization, or new electrochemical cells for photocurrent measurement. In summary, this report will see initial characterization of the processes, both light and dark, that occur within the triple phase boundary of a microdroplet for a given redox molecule dissolved within. Early attempts at coupling excited states with other molecules are also explored. Serendipity has always played a part in scientific discovery and the work outlined in this report was no different. The choice of oil used for the organic phase microdroplet deposits yielded some interesting and unexpected results, and has been implicated as one of the key aspects of the photoreactions that have been explored.

Mohsen, Hassan. "Estimations uniformes pour des problèmes de transmission à changement de signe : Liens avec les triplets de frontière et la quantification de l’incertitude". Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0227.

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Présentation du domaine: Il s'agit d'étudier des opérateurs différentiels sur des variétés riemanniennes singulières et leurs applications. Parmi les opérateurs les plus importants, on trouve les opérateurs de Laplace et de Dirac. Il y a beaucoup de connexions entre les deux types d'opérateurs, à cause de la formule de Lichnerowicz, un mathématicien français du dernier siècle. Pourtant, les opérateurs de Laplace ont été beaucoup plus étudiés que les opérateurs de Dirac. Les opérateurs de Dirac, aussi appelé opérateurs d'Atiyah--Singer, sont des opérateurs fondamentaux dans la géométrie riemannienne et dans la théorie de l'indice. Ce sont des opérateurs associés à une métrique et à un fibré de Clifford doté d'une connexion admissible. Leurs généralisations est l'objet principal dans la théorie de Kasparov, qui est un utile fondamental dans les algèbres d'opérateurs. Il y a beaucoup de gens qui pensent que les opérateurs de Dirac joueront un rôle central dans le programme de Grothendieck: généraliser le théorème de Riemann--Roch aux variétés algébriques singulières. Les opérateurs de Dirac ont donc été beaucoup étudiés dans les mathématiques fondamentales, ainsi que dans ces applications. Les opérateurs de Maxwell et de de Rham sont des cas particuliers des opérateurs de Dirac. Les opérateurs de Dirac apparaissent dans beaucoup d'applications dans d'autres domaines des mathématiques et physique théorique, comme la théorie des champs dans l'espace-temps courbe ou la théorie de la relativité générale. Ces opérateurs constituent donc un lien entre les mathématiques fondamentales et ces applications. Sujet de thèse: Il y a beaucoup de résultats sur l'analyse des opérateurs de Dirac, mais la plupart d'eux sont sur des variétés compactes lisses, avec ou sans bord. Cependant, il est important d'étudier ces opérateurs pour des variétés non compactes ou non lisses. Par exemple, les applications aux variétés algébriques et au programme de Grothendieck nécessitent le cas non lisse. Le sujet que nous proposons est d'utiliser les résultats et les techniques introduites par Monique Dauge et ses collaborateurs pour étudier les singularités des opérateurs de Dirac dans un domaine polyédrique et d'autres domaines singuliers. Un problème particulier est d'obtenir l'application au calcul de l'homologie de Rham avec des complexes finis, comme dans les travaux récents de Douglas Arnold. Pour la régularité des solutions de l'équation de Dirac, nous proposons d'utiliser les méthodes introduites récemment par Bernd Amman et Nadine Grosse ou par Victor Nistor et Nadine Grosse dans des articles récents. Nous allons étudier aussi les opérateurs de Dirac avec des potentiels et terms non linéaires. Un problème concret ici est d'étudier de modèles non linéaires couplés avec Maxwell, par exemple les modèles de magnéto-hydrodynamique et l'équation de Vlasov--Maxwell
General description of the domain. The general question that will be pursued as part of the thesis will be to study differential operators on Riemannian spaces and their applications. The Laplace and Dirac operators are among the most important differential operators arising in applications. There are many connections between these two types of operators, due to Lichnerowicz' formula, a French mathematician of the last century. However, Laplace operators have been much more studied than the Dirac operators. Dirac operators, also called Atiyah--Singer operators, are fundamental operators in Riemannian geometry and in index theory. These operators are associated to a metric and a Clifford bundle with an admissible connection. Their generalizations are the main object in Kasparov's theory, which is a fundamental theory in Operator Algebras. It is believed that the Dirac operators will play a central role in Grothendieck's program to generalize the Riemann--Roch theorem to singular algebraic varieties. Dirac operators have therefore been much studied in theoretical mathematics, as well as in its applications. The Maxwell and de Rham operators are special cases of Dirac operators. Dirac operators appear in many applications in other domains of mathematics and theoretical physics, such as field theory in curved space-time or the theory of general relativity. These operators are thus a link between the fundamental mathematics and its applications. Theses subject: There are many results on the analysis of the Dirac operators, but most of them are on smooth compact varieties, with or without boundary. However, it is important to study these operators for non-compact or non-smooth spaces (or varieties). For example, applications to algebraic varieties and to the Grothendieck program require the case of non smooth varieties. The subject we propose to use the results and the techniques introduced by Monique Dauge and her collaborators to study the singularities of the Dirac operators in a polyhedral domain and other singular domains. A particular problem is to obtain the application to the calculation of de Rham's homology with finite complexes, as in the recent works of Douglas Arnold. For the regularity of the solutions of the Dirac equation we propose to use the methods recently introduced by Bernd Amman and Nadine Grosse or by Victor Nistor and Nadine Grosse in recent articles. The thesis will also study the Dirac operators with nonlinear terms and potentials. A concrete problem here is to study nonlinear models coupled with Maxwell's equation, which arrise, for example in magneto-hydrodynamic models and in the Vlasov-Maxwell equation

Soltanzadeh, Marjan. "Modeling Triple Phase Boundary (TPB) in Solid Oxide Fuel Cell (SOFC) Anode". Thesis, University of Ottawa (Canada), 2010. http://hdl.handle.net/10393/28843.

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The idea of having the triple phase boundary (TPB) is extensively used in the fuel cell literature, especially with respect to solid oxide fuel cells (SOFC). The TPB concept indicates that the hydrogen oxidation reaction and the oxygen reduction reaction, which produce electric current, can actually occur at special sites, called "triple phase boundaries" where the gaseous fuel phase, ion conducting phase: electrolyte, and electron conducting phase, come into contact. Recent study shows that despite the common assumption about TPB, it is not just a point, but a zone that consists of two lines. The kinetic reaction often introduces a significant limitation to fuel cell performance. Therefore, understanding, characterizing, and optimizing the TPB content in fuel cells provides excellent opportunities for performance improvement. Studying the kinetics of the reaction that takes place at the triple phase boundary is one aspect of this paper. It includes the study of all kinds of chemical and electrochemical reactions as well as their reaction rates, the surface species, and the electrochemical parameters, such as reaction rate constants and conductivity. A mathematical model is developed to describe a simplified anodic solid oxide fuel cell (SOFC) system, Ni/ H2--H 2O/YSZ, and its reaction occurring in the vicinity of the triple phase boundary (TPB). The model incorporates coupled diffusion, migration and reaction phenomena of the chemical components in the gas phase, Ni particle and zirconia solid state. The kinetic constants necessary for the simulations are estimated on the basis of literature data.

Wang, Chingfu. "Triple phase boundary engineering of electrodes for solid oxide fuel cells by inkjet printing". Thesis, University of Cambridge, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708301.

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Pabit, Edgardo L. "Grain boundary and triple junction chemistry of silicon carbide sintered with minimum additives for armor applications". [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0012140.

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Zhou, Yijian. "Effects of grain boundary and triple line structures on carbide precipitation in type 304L stainless steel". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0019/MQ54131.pdf.

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Aljohani, Abdulrahman. "Applications of triple deck theory to study the flow over localised heating elements in boundary layers". Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/applications-of-triple-deck-theory-to-study-the-flow-over-localised-heating-elements-in-boundary-layers(a3174ce1-f4db-47d8-b0a7-a712461a8211).html.

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In this thesis, we investigate flow past an array of micro-electro-mechanical-type (MEMS-type) heating elements placed on a flat surface, where MEMS devices have hump-shaped surfaces, using the triple deck theory. In this work we start by investigating the problem with a single heating element. MEMS devices can be used to control the fluid dynamics over the surface. Hence, we present a review of the boundary layer and the triple deck theories, followed by a literature review of the problem of flow past an array of MEMS devices. Next, we formulate our problem with the aid of the method of matched expansions for supersonic and subsonic flows. Thirdly, we solve analytically the linear version of the problem for supersonic flows. Thereafter, the non-linear problem is solved numerically where a detailed description of a hybrid method to solve the formulated non-linear problem for supersonic flow is exhibited. Fourthly, for subsonic flows we continue investigating flow past a heating element placed on a flat surface. Linear analysis of this problem is conducted. A novel numerical method to solve the non-linear problem for subsonic flows is described. The results are then discussed. In a similar context, we formulate a problem which can be considered as an the extension of previous subsonic flow problem to the three dimensional case. Analytical results are obtained using the Fourier transform where the linear approximation of the problem is considered and numerical results are then obtained using the Fast Fourier Transform. Finally, we consider a case of transonic flow past a heating element placed on a flat surface, where MEMS device has a hump-shaped surface. This transonic flow problem is non-linear in the upper deck and the lower deck equations where they should be solved simultaneously. Hence, a numerical method is required where we will use a finite difference method in stream-wise direction and Chebyshev collocation method in the wall normal direction. The results are then analysed. In conclusion, the use of localised heating elements in boundary layers for flow types considered in the thesis can contribute to the possibility of favourably controlling the fluid flow perturbations.

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Libri sul tema "Boundary triples":

Gross, Thomas F. Bottom boundary layer stress measurements with BASS tripods: Data report STRESS 1988-89. [Woods Hole, Mass.]: Woods Hole Oceanographic Institution, 1993.

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Zhou, Yijian. Effects of grain boundary and triple line structures on carbide precipitation in type 304L stainless steel. Ottawa: National Library of Canada, 2000.

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Gross, Thomas F. Data report: Stress measurements in the bottom boundary layer with BASS tripods STRESS II 1990-91. [Woods Hole, Mass.]: Woods Hole Oceanographic Institution, 1993.

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Ruban, Anatoly I. Boundary-Layer Separation. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199681754.003.0003.

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Chapter 2 discusses the experimental observations of the boundary-layer separation in subsonic and supersonic flows that lead to a formulation of the concept of viscous-inviscid interaction. It then turns to the so-called ‘self-induced separation’ of the boundary layer in supersonic flows. This theory is formulated based on the asymptotic analysis of the Navier–Stokes equations at large values of the Reynolds number. As a part of the flow analysis, this chapter also introduces the ‘triple-deck model’. It then shows how this model may be used to describe the classical problem of the boundary-layer separation in an incompressible fluid flow past a circular cylinder.

Ruban, Anatoly I. Introduction. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199681754.003.0001.

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This book investigates high-Reynolds number flows, and analyses flows that can be described in the framework of Prandtl’s 1904 classical boundary-layer theory, including Blasius’s boundary layer on a flat plate, Falkner–Skan solutions for the boundary layer on a wedge surface, and other applications of Prandtl’s theory. It then discusses separated flows, and considers the so-called ‘self-induced separation’ in supersonic flow, and which led to the ‘triple-deck model’. It also presents Sychev’s 1972 theory of the boundary-layer separation in an incompressible fluid flow past a circular cylinder. It discusses the triple-deck flow near the trailing edge of a flat plate, and then considers the incipience of the separation at corner points of the body surface in subsonic and supersonic flows. It covers the Marginal Separation theory—a special version of the triple-deck theory—and describes the formation and bursting of short separation bubbles at the leading edge of a thin aerofoil.

Fortier, Pascal. Triple junction and grain boundary distributions in metallic materials. 1996.

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Ruban, Anatoly I. Fluid Dynamics. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199681754.001.0001.

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This is Part 3 of a book series on fluid dynamics. This is designed to give a comprehensive and coherent description of fluid dynamics, starting with chapters on classical theory suitable for an introductory undergraduate lecture courses, and then progressing through more advanced material up to the level of modern research in the field. This book is devoted to high-Reynolds number flows. It begins by analysing the flows that can be described in the framework of Prandtl’s 1904 classical boundary-layer theory. These analyses include the Blasius boundary layer on a flat plate, the Falkner-Skan solutions for the boundary layer on a wedge surface, and other applications of Prandtl’s theory. It then discusses separated flows, and considers first the so-called ‘self-induced separation’ in supersonic flow that was studied in 1969 by Stewartson and Williams, as well as by Neiland, and led to the ‘triple-deck model’. It also presents Sychev’s 1972 theory of the boundary-layer separation in an incompressible fluid flow past a circular cylinder. It discusses the triple-deck flow near the trailing edge of a flat plate first investigated in 1969 by Stewartson and in 1970 by Messiter. It then considers the incipience of the separation at corner points of the body surface in subsonic and supersonic flows. It concludes by covering the Marginal Separation theory, which represents a special version of the triple-deck theory, and describes the formation and bursting of short separation bubbles at the leading edge of a thin aerofoil.

Azaryan, Sergey, e Tigran Grigoryan. Application of Integrals and Ordinary Differential Equations in Physics Problems. YSU press, 2023. http://dx.doi.org/10.46991/ysuph/9785808426498.

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The manual is intended for 1st and 2nd year students of YSU Faculty of Physics. In the first chapter of the manual, boundary problems of physics have been considered, the solutions of which lead to the calculation of definite, curvilinear, double, triple, surface integrals, as well as the limits of integral sums. In the second chapter, such boundary problems of physics have been included, which are brought to the application of ordinary differential equations of the first and second order. Solved problems and tasks on the topics discussed in the educational manual will increase the level of students’ knowledge.

Ruban, Anatoly I. Incipient Separation Near Corners. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199681754.003.0005.

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Chapter 4 analyses the transition from an attached flow to a flow with local recirculation region near a corner point of a body contour. It considers both subsonic and supersonic flow regimes, and shows that the flow near a corner can be studied in the framework of the triple-deck theory. It assumes that the body surface deflection angle is small, and formulates the linearized viscous-inviscid interaction problem. Its solution is found in an analytic form. It also presents the results of the numerical solution of the full nonlinear problem. It shows how, and when, the separation region forms in the boundary layer. In conclusion, it suggests that in the subsonic flow past a concave corner, the solution is not unique.

Ruban, Anatoly I. Marginal Separation Theory. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199681754.003.0006.

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Chapter 5 discusses the ‘short separation bubble’ that forms at the leading edge of an aerofoil when the angle of attack reaches a certain value. It then suggests that the process of the formation of the bubble is described by the Marginal Separation theory, which represents a special version of the triple-deck theory. It then covers how, in this case, the viscous-inviscid interaction problem may be reduced to an integro-differential equation for the skin friction. It discusses how by solving this equation not only the transition from attached to separated flow in the boundary layer be predicted, but also the well-known phenomenon of the ‘bubble bursting’ that leads to a sudden loss of the lift produced by an aerofoil.

Capitoli di libri sul tema "Boundary triples":

Brown, B. Malcolm, Marco Marletta e Ian Wood. "Working with Sergey Naboko on Boundary Triples". In From Complex Analysis to Operator Theory: A Panorama, 3–10. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-31139-0_1.

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Behrndt, Jussi, e Hagen Neidhardt. "Scattering matrices and Weyl functions of quasi boundary triples". In Analysis as a Tool in Mathematical Physics, 162–82. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-31531-3_12.

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Post, Olaf. "The Functional Analytic Part: Scales of Hilbert Spaces and Boundary Triples". In Lecture Notes in Mathematics, 97–185. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-23840-6_3.

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Behrndt, Jussi, e Peter Schlosser. "Quasi Boundary Triples, Self-adjoint Extensions, and Robin Laplacians on the Half-space". In Linear Systems, Signal Processing and Hypercomplex Analysis, 49–66. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-18484-1_2.

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Dell’Antonio, Gianfausto. "Lecture 20: Self-adjoint Extensions. Relation with Quadratic Forms. Laplacian on Metric Graphs. Boundary Triples. Point Interaction". In Atlantis Studies in Mathematical Physics: Theory and Applications, 429–54. Paris: Atlantis Press, 2015. http://dx.doi.org/10.2991/978-94-6239-118-5_20.

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Nakatani, Naoki, Jia-Jia Zheng e Shigeyoshi Sakaki. "Approach of Electronic Structure Calculations to Crystal". In The Materials Research Society Series, 209–55. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-0260-6_11.

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AbstractNowadays, the importance of molecular crystals and solids with regular structures is increasing in both basic chemistry and applied fields. However, theoretical studies of those systems based on electronic structure theories have been limited. Although density functional theory (DFT) calculations using generalized gradient approximation type functional under periodic boundary condition is effective for such theoretical studies, we need some improvements for calculating the dispersion interaction and the excited state of crystals. Accordingly, in this chapter, two methods for calculating the electronic structures of molecular crystals are discussed: cluster-model/periodic-model (CM/PM)-combined method and quantum mechanics/periodic-molecular mechanics (QM/periodic-MM) method. In the CM/PM-combined method, an infinite crystal system is calculated by the DFT method under periodic boundary condition, and important moieties, which are represented by CMs, are calculated by either DFT method with hybrid-type functionals or wave function theories such as the Møller–Plesset second-order perturbation theory (MP2), spin-component-scaled-MP2, and coupled-cluster singles and doubles theory with perturbative triples (CCSD(T)). This method is useful for gas adsorption into crystals such as metal–organic frameworks. In the QM/periodic-MM method, an important moiety is calculated using a QM method such as the DFT method with hybrid-type functionals and wave function theories, where the effects of the crystal are incorporated into the QM calculation via the periodic MM method using a classical force field. This method is useful for theoretical studies of excited states and chemical reactions. The applications of these methods in the following processes are described in this chapter: adsorption of gas molecules on metal–organic frameworks, chemical reactions in crystals, and luminescence of the crystals of transition metal complexes. To the best of our knowledge, the theoretical calculations conducted in this chapter show one of the successful approaches of electronic structure theories to molecular crystals, because of the reasonable and practical approximations.

Duck, P. W. "Unsteady Triple-deck Flows Leading to Instabilities". In Boundary-Layer Separation, 297–312. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-642-83000-6_17.

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Behrndt, Jussi, Seppo Hassi e Henk De Snoo. "Boundary Triplets and Weyl Functions". In Boundary Value Problems, Weyl Functions, and Differential Operators, 107–67. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-36714-5_3.

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Schmüdgen, Konrad. "Self-adjoint Extensions: Boundary Triplets". In Graduate Texts in Mathematics, 307–41. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-94-007-4753-1_14.

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Behrndt, Jussi, Seppo Hassi e Henk De Snoo. "Boundary Triplets and Boundary Pairs for Semibounded Relations". In Boundary Value Problems, Weyl Functions, and Differential Operators, 281–364. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-36714-5_6.

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Atti di convegni sul tema "Boundary triples":

Lotoreichik, V., H. Neidhardt e I. Yu Popov. "Point contacts and boundary triples". In QMath12 – Mathematical Results in Quantum Mechanics. WORLD SCIENTIFIC, 2014. http://dx.doi.org/10.1142/9789814618144_0024.

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Shang, Yu-Ming, Heyan Huang, Xin Sun, Wei Wei e Xian-Ling Mao. "Relational Triple Extraction: One Step is Enough". In Thirty-First International Joint Conference on Artificial Intelligence {IJCAI-22}. California: International Joint Conferences on Artificial Intelligence Organization, 2022. http://dx.doi.org/10.24963/ijcai.2022/605.

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Extracting relational triples from unstructured text is an essential task in natural language processing and knowledge graph construction. Existing approaches usually contain two fundamental steps: (1) finding the boundary positions of head and tail entities; (2) concatenating specific tokens to form triples. However, nearly all previous methods suffer from the problem of error accumulation, i.e., the boundary recognition error of each entity in step (1) will be accumulated into the final combined triples. To solve the problem, in this paper, we introduce a fresh perspective to revisit the triple extraction task and propose a simple but effective model, named DirectRel. Specifically, the proposed model first generates candidate entities through enumerating token sequences in a sentence, and then transforms the triple extraction task into a linking problem on a ``head -> tail" bipartite graph. By doing so, all triples can be directly extracted in only one step. Extensive experimental results on two widely used datasets demonstrate that the proposed model performs better than the state-of-the-art baselines.

Boitsev, A. A. "Boundary triplets approach for Dirac operator". In QMath12 – Mathematical Results in Quantum Mechanics. WORLD SCIENTIFIC, 2014. http://dx.doi.org/10.1142/9789814618144_0015.

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Sharma, Nitika, Simranjit Kaur e Balwinder S. Dhaliwal. "A new triple band hybrid fractal boundary antenna". In 2016 IEEE International Conference on Recent Trends in Electronics, Information & Communication Technology (RTEICT). IEEE, 2016. http://dx.doi.org/10.1109/rteict.2016.7807953.

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Svanadze, Merab. "Boundary Value Problems in the Theory of Thermoelasticity for Triple Porosity Materials". In ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-65046.

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This paper concerns with the quasi static linear theory of thermoelasticity for triple porosity materials. The system of governing equations based on the equilibrium equations, conservation of fluid mass, the constitutive equations, Darcy’s law for materials with triple porosity and Fourier’s law of heat conduction. The cross-coupled terms are included in the equations of conservation of mass for the fluids of the three levels of porosity (macro-, meso- and micropores) and in the Darcy’s law for materials with triple porosity. The system of general governing equations is expressed in terms of the displacement vector field, the pressures in the three pore systems and the temperature. The basic internal and external boundary value problems (BVPs) are formulated and on the basis of Green’s identities the uniqueness theorems for the regular (classical) solutions of the BVPs are proved. The surface (single-layer and double-layer) and volume potentials are constructed and their basic properties are established. Finally, the existence theorems for classical solutions of the BVPs are proved by means of the potential method and the theory of singular integral equations.

Zhang, Yice, Yifan Yang, Yihui Li, Bin Liang, Shiwei Chen, Yixue Dang, Min Yang e Ruifeng Xu. "Boundary-Driven Table-Filling for Aspect Sentiment Triplet Extraction". In Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing. Stroudsburg, PA, USA: Association for Computational Linguistics, 2022. http://dx.doi.org/10.18653/v1/2022.emnlp-main.435.

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Pehrson, John C., Boris S. Leonov, Richard B. Miles, Christopher Limbach e Matthew T. Lakebrink. "Hypersonic Tripped Boundary Layer Measurements using FLEET Velocimetry". In AIAA AVIATION 2022 Forum. Reston, Virginia: American Institute of Aeronautics and Astronautics, 2022. http://dx.doi.org/10.2514/6.2022-3477.

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Zhang, Weihan, e Ming C. Leu. "Surface Reconstruction From Triple Dexel Model for Virtual Sculpting". In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-35175.

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This paper presents a novel method for surface reconstruction from triple dexel data for virtual sculpting. A triple dexel based virtual sculpting system is developed to provide the capability of interactive solid modeling with haptic interface. A solid model is converted to triple dexel data, which depicts the intersections of the solid with rays cast in three orthogonal directions, and modified during the virtual sculpting process. The boundary of the tool swept volume is computed based on the Sweep Differential Equation method. Contour generation and combination algorithms convert the triple dexel data to three sets of orthogonal slices of contours. A tiling algorithm then generates the solid’s boundary surface in triangular facets from these contours. Examples are given to demonstrate the ability of the developed method and software to realistically simulate the physical sculpting process and to allow viewing the sculpted models in any directions.

CHOU, J., e M. CHILDS. "The passive control of compressible boundary layer growth by boundary layer trips". In Shear Flow Control Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1985. http://dx.doi.org/10.2514/6.1985-561.

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Zhang, Xiaohang, Frank Marken e Christopher A. Paddon. "Screening Anti-Oxidant Activity at Oil Microdroplet Triple Phase Boundary Electrodes". In 9th International Conference on Engines and Vehicles. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2009. http://dx.doi.org/10.4271/2009-24-0103.

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Rapporti di organizzazioni sul tema "Boundary triples":

A.H. King and M.A. Dayananda. Diffusion in Grain Boundary Triple Junctions, and its Effects on the Behavior of Nanostructured Materials. Office of Scientific and Technical Information (OSTI), dicembre 2006. http://dx.doi.org/10.2172/896482.

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