1,721,034 research outputs found
Of Castrati, Angels and Simians. Ernesto Tomasini interviewed by Serena Guarracino
No full textIn this interview, Ernesto Tomasini and Serena Guarracino explore the multifarious possibilities of the voice of ‘queering’ normative notions of identity and subjectivity. Journeying across the many personifications of Tomasini’s own voice – from castrato to digital angel – their dialogue starts from Butler’s notion of ‘drag’ to show how the questioning of gender identity actually entails putting into question the body as neutral signifier of a human identity. Contemporary musical and artistic practices can redraw the boundaries of the performative body. Seventeenth-century castrati remind our present of an excessive technology of the body that challenges the border between the human and the monstrous. Tomasini’s art short-circuits these (and other) experiences of the performative body, opening it up to endless possibilities of impersonation
Experimental Verification of Flow Characteristics Across Models of Straight Through and Other Geometry Labyrinth Seals by Laser Doppler Anemometer
No full textUna indagine sperimentale con anemometro laser Doppler in modelli ingranditi di tenute a labirinto di interesse industriale, coadiuvata da visualizzazioni del flusso, ha permesso di individuare i fenomeni fluidodinamici di maggiore rilevanza, per il verificarsi dell’azione di limitazione della portata di perdita attraverso differenti geometrie.In this paper an experimental study is described concerning enlarged models of labyrinth seals of different geometries. LDA measurements have been carried out togheter with flow visualization in order to get information about the most important fluid dynamic mechanisms for leakage limitation
A Computation and Measurement Analysis about the Evaluation of the Stator-Rotor Clearance on a Test Rig for Labyrinth Seals
No full textLa pubblicazione descrive le procedure di previsione e di verifica sperimentale dell’incertezza di alcune grandezze misurate (gioco, temperatura del fluido, etc.), durante le prove sul banco-tenute in scala reale della Società Nuovo Pignone e le modalità di riduzione dell’incertezza della misura indiretta dei coefficienti di flusso delle diverse tenute.In this paper the procedures are described of prediction and experimental evaluation of uncertainty concerning some parameters of interest in the performance evaluation of labyrinth seal of different geometry to be used in high pressure centrifugal compressors
Subsonic jet pressure fluctuation characterization by tomographic laser interferometry
No full textThis paper describes the application of a nonconventional experimental technique based on optical interferometry for the characterization of aeroacoustic sources. The specific test case studied is a turbulent subsonic jet. Traditional experimental methods exploited for the measurement of aerodynamic velocity fields are laser Doppler anemometer and particle image velocimetry which have an important drawback due to the fact that they can measure only if the flow is seeded with tracer particles. The technique proposed, by exploiting a laser Doppler interferometer and a tomographic algorithm for 3D field reconstruction, overcomes the problem of the flow seeding since it allows directly measuring the flow pressure fluctuation due to the flow turbulence. A laser Doppler interferometer indeed is sensitive to the density oscillation within the medium traversed by the laser beam even though it integrates the density oscillation along the entire path traveled by the laser. Consequently, the 3D distribution of the flow density fluctuation can be recovered only by exploiting a tomographic reconstruction algorithm applied to several projections. Finally, the flow pressure fluctuation can be inferred from the flow density measured, which comprehends both the aerodynamic pressure related to the turbulence and the sound pressure due to the propagation of the acoustic waves into the far field. In relation to the test case studied in this paper, e.g., the turbulent subsonic jet, the method allows a complete aeroacoustic characterization of the flow field since it measures both the aerodynamic "cause" of the noise, such as the vortex shedding, and the acoustic "effect" of it, i.e., the sound propagation in the 3D space. The performances and the uncertainty have been evaluated and discussed, and the technique has been experimentally validated
Studio di un Diaframma in Flusso Pulsante
No full textnel lavoro si descrivono le procedure di acquisizione ed elaborazione dei dati di velocità, specifiche per regime pulsante, le tecniche di integrazione dei profili di velocità ed alcuni dei risultati ottenuti. In esso vengono inoltre discussi alcuni aspetti relativi alla accuratezza delle misure di portata ottenute per integrazione, anche con riferimento alle caratteristiche della sezione di prova utilizzata per la sperimentazione descritta in questo lavor
New non-contact fiber optic sensor for measurement of bubble velocity in two-phase flow
No full textDifferent kinds of probes have been proposed for the measurement of void fraction, bubble dimension and velocity in two phase flows. All these probes require the interaction between the bubbles and a solid sensing element so that flow disturbance and bubble deformation occurs. In this paper a new non-contact sensing element is described. This new sensing element is based on the interaction between the bubble and two focalized laser beams. The measurement principle is that known as transit-time technique used, for example, in laser dual focus velocimetry or cross-correlation based measuring systems. The object measurement system is based on optical fiber components. The probe is designed for measurements on two-phase flows with minimal disturbance to the flow, since no contact between the bubble and the probe tip is achieved. The probe has been tested in an hydraulic test rig circulated by a vertical two-phase air-water flow at different velocities. The test section that was used is a 100 mm in diameter vertical plexiglass tube. Nitrogen gas was injected upstream the probe in order to obtain small spherical bubbles, with variable bubble concentration, shape and dimensions, to better characterize the probe. The reference bubble velocity was measured independently using photographic techniques and by means of an LDV system
Underwater image pre-processing for photogrammetric application
No full textThis work describes a new method for correcting underwater images acquired under natural illumination condition and targeted to photogrammetry for 3D object reconstruction. In particular, a comparison between the new approach and a previous one from literature is presented. The new approach demonstrated to be a feasible and robust solution to improve quality, colour and contrast in underwater imaging by means of a three-step procedure. The focus of the paper is on 3D reconstruction of small-sized corals in shallow water. The colour of pre-processed images, with a visible green-blue colour cast, are enhanced and the higher images quality eases the whole object reconstruction acquired in a poor visible scene. The higher performance of the proposed method is experimentally demonstrated
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