1,722,067 research outputs found
Les Caroli Pondus conservés en Italie
No full textCapobianchi V. Les Caroli Pondus conservés en Italie. In: Mélanges d'archéologie et d'histoire, tome 20, 1900. pp. 43-77
[Calisto Zorzi and Anna Capobianchi Zorzi (1886), funerary sculpture]
No full textFrom Berresford: Calisto Zorzi and Anna Capobianchi Zorzi (1886), Ugo Zannoni, Cimitero Monumentale, Verona.Group depicting man giving charity to children, a mother and child, and a worker with hand tools placing flowers at the man's feet.Title from Berresford
Il venditore d’antichità by Vincenzo Capobianchi (1880): possibly the most scholarly work of the neo-Pompeian painting
Get PDFCette étude porte sur la structure et le contexte artistique du tableau peint en 1880 par Vincenzo Capobianchi : Il venditore d’antichità. Elle se penche d’abord sur l’auteur qui commença sa carrière comme peintre avant de se centrer sur le commerce de l’art et la numismatique. Elle examine ensuite les « marchands d’antiquités » comme un sous-genre de la peinture néo-pompéienne, avant d’identifier l’extraordinaire assemblage de chefs-d’œuvre ici rassemblés par Capobianchi. Il venditore d’antichità apparaît à la fois comme unique et emblématique. Au-delà de l’attrait immédiat provoqué par cette charmante scène de rue, peinte avec une technique quasi-photographique (de la qualité des artistes les plus reconnus de l’époque tels Alma-Tadema et Siemiradzky), ce tableau résonne comme une forte dénonciation sociale d’un Empire romain prédateur, une image seyante et anticipée du débat contemporain sur le centre et la périphérie.This paper explores the structure and artistic context of Il venditore d’antichità, painted by Vincenzo Capobianchi in 1880. It first describes its author who started his career as a painter before concentrating on art dealing and numismatics. It then takes into consideration the “seller of antiquities” as a subgenre of the Neo-Pompeian painting, before identifying the extraordinary array of masterworks here displayed by Capobianchi. It is argued that Il venditore d’antichità is both unique and emblematic. Beyond the immediate appeal of this charming street view, painted with a near photographic technique (not inferior to the most acclaimed artists of the time, such as Alma-Tadema of Siemiradzky), this painting constitutes a strong social denunciation of the predatory Roman Empire, a suitable and anticipated image for the contemporary “Center-Periphery” issue
Computational fluid dynamics simulations of cavitating flows and numerical modelling of cavitation damage
No full textIn this thesis, Computational Fluid Dynamics (CFD) simulations are used to numerically model cavitation on different geometries: a NACA-66 (mod) hydrofoil profile, a horizontal axis tidal turbine (HATT) and an impinging nozzle test case. The Singhal (FCM) and the Schnerr and Sauer (SSCM) cavitation models have been selected from the literature, they are both based on the non-compressible bubble dynamics equation of Rayleigh-Plesset. Turbulence assessments involve the use of the Transitional Shear Stress Transport (TSST), the Scale Adaptive Simulation (SAS) and the Shear Stress Transport (SST) k-omega turbulence models to achieve the Reynolds Average Navier Stokes (RANS) equations closure. Based on the theory of Plesset, Chapmann and Lush a new cavitation damage index, capable to map the damage of solid boundaries due to vapour collapse has been proposed. Initially, in Chapter 1 a review of the major works contributing to the state of the art of cavitation and cavitation damage modelling is presented. Chapter 2 describes the physics of cavitation and cavitation induced damage, treating in depth phenomena ranging from bubble dynamics to water jet formations due to single bubble implosions. In Chapter 3, fundamental laws of turbulent and cavitating flows have been presented. The theoretical treatment involves derivation of the Navier-Stokes equations, presentation of the RANS approach used to model the cavitating flows and description of the turbulence models selected to close the RANS system. Then, the main equations ruling the mass transfer mechanisms are mentioned for both the FCM and SSCM, detailing peculiarities of each cavitation model. At the end of the Chapter, the formulation of a numerical framework aimed at defining a new cavitation damage index is explained. Its theoretical assumptions and the implementation are reported as well. In Chapter 4, the standard TSST and SAS turbulence models are used in conjunction with the FCM to detect pressure coefficients on the NACA-66 (mod) profile. Predicted results are compared to the experimental findings of Shen and Dimotakis. In Chapter 5 the Reboud density function is implemented to adjust the eddy viscosity computation with respect to the standard turbulence modelling. New results obtained on the same hydrofoil profile used in Chapter 4 are substantially improved in the cavitation region when the FCM is selected in combination with the SST k-omega turbulence model. The combination of the Reboud corrected turbulence model and the FCM is then exported to simulate cavitation occurrence for four different rotating conditions on a selected HATT. Cavitating simulations are performed at the end of a Mesh Sensitivity Analysis (MSA) aimed at identifying the optimal computational grid in terms of both turbine power and thrust. Final cavitation simulations reveal that the severest risk of cavitation inception occurs outside of the machine operating regime. In the end (Chapter 6), the work focuses on a campaign of simulations dedicated to validate the proposed cavitation damage model on the nozzle test case of Franc. The optimal computational grids are selected performing a MSA in terms of both static pressure and velocity magnitude. Results have been obtained by testing the corrected SST k-omega turbulence model and the cavitation damage model in conjunction with the FCM and the SSCM, with the latter returning the best performance in terms of damage peak location when the finest time step condition is implemented. Conclusions and future developments, exposed in Chapter 7, complete the thesis argumentation reporting the main outcomes of the work and its possible industrial applications
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Analysis of the water injection process in industrial gas turbines axial compressor
Get PDFIn this work, the water injection process in the AXial COmpressor (AXCO) of industrial Gas Turbines (GT) has been analyzed to identify the benefits on the GT operation and the associated risks for GT and AXCO mechanical integrity. Water injection is a technique in which a flow of water is injected and dispersed at the suction of industrial Gas Turbines. This technique has been largely used either for washing purposes or to improve GT output power in specific conditions. In the water washing application, the water injection allows to recover the performance losses due to fouling of the GT internals, while in the power augmentation application, water injection is used to increase GT power output. Although the water injection has shown to be effective in both applications, site experiences demonstrated that it could yield to components erosion with most of the damages detected in the Leading Edge section of the AXCO first stage rotor blades. Since the control and reduction of performance detriment due to AXCO fouling is of paramount importance for an industrial GT operation, the present work is focused on the water washing application; however, some of the results could be extended also to power augmentation application. Through the analyses of the present work, the leading design parameters of the water injection system have been identified to provide a design guideline for the optimized design and optimized operation of the water washing devices. The effects of the water washing have also been assessed in terms of carbon footprint reduction of a typical industrial GT. To identify the effects of the water injection on the GT AXCO, a dedicated Water Droplets Erosion (WDE) model has been developed and assessed against the available models. The WDE has been
developed considering the effects of a wide range of droplets diameters combined with the introduction of specific materials properties characterized through a dedicated experimental campaign. The model demonstrated a clear improvement compared to the models available in literature, improving the main limitations related to the droplets’ dimeters and blades material selection. The novel WDE has shown consistency with experimental results when considering a wide range of droplets diameters and when considering specific GT AXCO material characteristics. To reduce the number of variables to be considered in the performance and design space definition, a sensitivity analysis on the WDE leading parameters has been performed on simplified GT geometries through means of CFD simulations. The results highlighted the role of the injection time and of the angle and velocity of injection as the parameters with larger effect on the washing efficiency. The injection location and the droplet size distribution seem to be the leading parameters to control the water droplets distribution on the AXCO blade.
Based on the results of the sensitivity analyses, the novel WDE has been applied on a real case where the complete geometry of a real GT has been considered form the inlet plenum up to the outlet of the first AXCO rotor. The results of CFD analyses coupled with the new WDE have been compared with field data and the shop analyses of a GT subjected to several water washing cycles. The comparison of the numerical results with the experimental field data has shown good 4 qualitative agreement, with the ability of highlight the impact regions and of predicting the overall component erosion. Based on the design and operations space highlighted through the simplified geometry analyses and based on the experimental verification of the model, a complete mapping of the water washing design and operation has been created. This mapping is currently being used to create a design tool for the design optimization of the water washing devices and a monitoring and diagnostic analytic to provide indications on the optimum settings of the water washing during operation. This analytic, will be able to provide real time guidance on the optimum water washing cycles, predicting GT efficiency recovery, highlighting mechanical integrity risks and, thanks to the LCA analyses and mapping, providing information on the resulting carbon footprint of the GT
Variations on the Author
Get PDF“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
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