86,522 research outputs found
"Pensées des morts. Paroles de de Lamartine. Musique de Félicien David" (manuscrit autographe)
No full textAu titre : "manuscrit F. O. Alizard. Pensée des morts dédiée à son ami Alizard par Félicien David. Octobre 1839". - Foliotation ajoutée. - Au fol. 6 v° "Mr Guillet. Rue Croix des Petits champs N°31.". - On a joint une partie de 2d hautbois (342 x 263 mm). - A la suite de cette partie, esquisse pré-instrumentale "Lever de soleil
"Pensées des morts. Paroles de de Lamartine. Musique de Félicien David" (manuscrit autographe)
No full textAu titre : "manuscrit F. O. Alizard. Pensée des morts dédiée à son ami Alizard par Félicien David. Octobre 1839". - Foliotation ajoutée. - Au fol. 6 v° "Mr Guillet. Rue Croix des Petits champs N°31.". - On a joint une partie de 2d hautbois (342 x 263 mm). - A la suite de cette partie, esquisse pré-instrumentale "Lever de soleil
Optimal transient growth in compressible turbulent boundary layers
No full textThe structure of zero-pressure-gradient compressible turbulent boundary layers is
analysed using the tools of optimal transient growth theory. The approach relies
on the extension to compressible flows of the theoretical framework originally
developed by Reynolds & Hussain (J. Fluid Mech., vol. 52, 1972, pp. 263–288) for
incompressible flows. The model is based on a density-weighted triple decomposition
of the instantaneous field into the contributions of the mean flow, the organized
(coherent) motions and the disorganized background turbulent fluctuations. The
mean field and the eddy viscosity characterizing the incoherent fluctuations are here
obtained from a direct numerical simulation database. Most temporally amplified
modes (optimal modes) are found to be consistent with scaling laws of turbulent
boundary layers for both inner and outer layers, as well as in the logarithmic
region, where they exhibit a self-similar spreading. Four free-stream Mach numbers
are considered: Ma ∞ = 0.2, 2, 3 and 4. Weak effects of compressibility on the
characteristics length and the orientation angles are observed for both the inner- and
the outer-layer modes. Furthermore, taking into account the effects of mean density
variations, a universal behaviour is suggested for the optimal modes that populate the
log layer, regardless of the Mach number. The relevance of the optimal modes in
describing the near-wall layer dynamics and the eddies that populate the outer region
is discussed
Sensitivity and forcing response in separated boundary-layer flow
No full textThe stability of separating boundary-layer flow on a flat plate is numerically investigated by means of three-dimensional
eigenmodes of the linearized Navier-Stokes equations obtained by linearization about the steady state. The disturbance variables
are approximated using a Chebyshev-Chebyshev collocation technique in inhomogeneous directions. Due to the large size of the
generalized eigenvalue problem, an Arnoldi iterations method using ARPACK routines is employed. By expanding the flow disturbance
variables in the basis of eigenmodes the growth potential is revealed by the computation of the optimal initial condition. This yields a
low-dimensional model of the flow and a unified view on its stability characteristics. Furthermore, a general formalism is developed to
assess how harmonic forcing may alter the stability properties of flows studied by a global approach of the linear stability theory. This
formalism is based on the sensitivity analysis performed by the pseudo-spectrum calculation and the resolution of the forced problem.
These results are compared and extended with direct numerical simulation
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
Global and Koopman modes analysis of sound generation in mixing layers
No full textIt is now well established that linear and nonlinear instability waves play a significant role in the noise generation process for a wide variety of shear flows such as jets or mixing layers. In that context, the problem of acoustic radiation generated by spatially growing instability waves of two-dimensional subsonic and supersonic mixing layers are revisited in a global point of view, i.e., without any assumption about the base flow, in both a linear and a nonlinear framework by using global and Koopman mode decompositions. In that respect, a timestepping technique based on disturbance equations is employed to extract the most dynamically relevant coherent structures for both linear and nonlinear regimes. The present analysis proposes thus a general strategy for analysing the near-field coherent structures which are responsible for the acoustic noise in these configurations. In particular, we illustrate the failure of linear global modes to describe the noise generation mechanism associated with the vortex pairing for the subsonic regime whereas they appropriately explain the Mach wave radiation of instability waves in the supersonic regime. By contrast, the Dynamic Mode Decomposition (DMD) analysis captures both the near-field dynamics and the far-field acoustics with a few number of modes for both configurations. In addition, the combination of DMD and linear global modes analyses provides new insight about the influence on the radiated noise of nonlinear interactions and saturation of instability waves as well as their interaction with the mean flow
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
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