1,721,648 research outputs found
Rutas Atlánticas : Redes narrativas entre América Latina y Europa
Full text linkNello sterminato archivio di attraversamenti che è l’Oceano Atlantico, nella distesa infinita dei suoi silenzi, fatti di brusche frenate e di violente accelerazioni, va ricercata l’origine di relazioni, confluenze, scritture e riscritture che sembrano convergere verso un unico macro-testo, che trascende lo spazio e il tempo e definisce i tratti fondamentali di una comunità culturale transcontinentale. Si tratta di una comunità umana fatta di intersezioni, rotte incrociate, continue e reciproche influenze, che si muove sullo scenario politico, socio-economico e culturale, attraverso i secoli, e per la quale l’operazione di selezione, classificazione e ordine, che è insita in ogni studio critico, deve necessariamente ricalibrarsi. In una prospettiva di ricerca intercontinentale e plurilingue, il volume Rutas Atlanticas. Redes narrativas entre América Latina y Europa si propone di raccogliere studi dedicati all’indagine delle relazioni d’influenza tra l’America Latina e l’Europa, nelle dimensioni della letteratura, delle culture e della storia. I quarantatré saggi raccolti nel volume, accompagnati da cinque interviste e da tre schede libro, esplorano un esteso bagaglio di rappresentazioni letterarie, filmiche, pittoriche, teatrali, architettoniche e musicali, di traiettorie storiche, biografiche e culturali, il cui risultato delinea un eterogeneo prisma di voci, pensieri e scritture tra i due mondi.In el inconmensurable archivo de travesías que es el Océano Atlántico, en la infinita extensión de sus silencios, hay que
buscar el origen de relaciones, confluencias, escrituras que parecen converger hacia un único macro-texto, que trasciende
el espacio y el tiempo y define los rasgos fundamentales de una comunidad cultural transcontinental. Se trata de una comunidad humana que se estructura por medio de continuas y recíprocas influencias, que se mueve en el escenario político, socio-económico y cultural, a través de los siglos, y para la cual la operación de selección, clasificación y orden, que
todo estudio crítico implica, debe necesariamente recalibrarse. La tarea que se propone este volumen es extensa y quizás
atrevida: hilar tejidos que recorran las relaciones y contactos entre América Latina y Europa, caminando las dimensiones de
la literatura, de las culturas y de la historia. Las texturas recolectadas en estas páginas exploran un extenso abanico
de representaciones literarias, fílmicas, pictóricas, teatrales, arquitectónicas y musicales, de derroteros históricos, biográficos y culturales, cuyo resultado delinea un animado prisma de voces entre mundos. En este desafío a la complejidad consiste
narrar las inagotables trayectorias, metafóricas y reales, que componen el volumen Rutas atlánticas
Transient Diffusion within Spherical Particles: Numerical Resolution of the Maxwell−Stefan Formulation
No full textThe generalized Maxwell−Stefan equations describe the mass-transfer process in a multicomponent mixture in different physical systems. This approach to the mass-transfer phenomenon has been largely used in particular for the simulation of the multicomponent diffusion in microporous systems. Our group has recently proposed (Leonardi, E.; Angeli, C. J. Phys. Chem. B 2010, 114, 151) a general numerical procedure for the resolution of the Maxwell−Stefan equations in the transient regime for one-dimensional systems. This procedure has been applied for the study of bulk diffusion, the uptake process on a microporous material, and permeation across a microporous membrane. In this paper this approach is extended to the case of diffusion within a sphere, which can be reduced to a one-dimensional problem in the presence of isotropy
Conoscenze in movimento per la Giustizia Ambientale: il caso del gasdotto TAP
Full text linkDa circa tre decenni osserviamo l’espansione e la diffusione, in Italia come nel mondo, della conflittualità socio-ambientale, che si configura sempre più come campo di partecipazione politica di soggetti esclusi e sperimentazione di nuove forme di opposizione. Nel libro questa tipologia di conflitti viene inserita nel campo della giustizia ambientale per sottolineare il tema politico delle disastrose conseguenze sociali prodotte dall’attuale sistema di sfruttamento delle risorse ambientali e dell’insufficienza delle strutture democratiche nella tutela dei diritti dei cittadini ad un territorio integro. In relazione a questa problematica, il particolare attivismo sul fronte delle conoscenze da parte delle parti sociali che animano una protesta evidenzia un conflitto anche di conoscenze e indica l’esistenza di luoghi e i modi di produzione, diffusione e utilizzo di conoscenza alternativi a quelli ufficialmente riconosciuti. Si danno quindi dei processi che influenzano le condotte sociali, consentono di ridiscutere categorie consolidate e conferiscono carattere politico a pratiche, quelle di opposizione, e temi, quelli relativi all’ambiente, che subiscono costantemente tentativi di depoliticizzazione. Attraverso la narrazione e l’analisi della dimensione epistemica delle proteste sorte in Italia in relazione alla costruzione del gasdotto TAP, il libro intende contribuire al dibattito su come si debba configurare lo spazio della politica ai tempi di una irreversibile crisi ecologica e in presenza di forze sociali che indicano, con forza e ampiezza crescenti, la fine della modernità nella relazione con la natura, la necessità del ridimensionamento delle forme della democrazia, l’importanza, nelle scelte che riguardano l’ambiente, dell’integrazione fra razionalità tecnica e culturale.
Le conoscenze come strumento di riconfigurazione di rapporti di potere, della relazione società-conoscenza e della relazione umanità-natura sono inserite in uno schema analitico applicabile ad altri casi empirici, che raramente sono analizzati da questa prospettiva
On the Maxwell−Stefan Approach to Diffusion: A General Resolution in the Transient Regime for One-Dimensional Systems
No full textThe diffusion process in a multicomponent system can be formulated in a general form by the generalized Maxwell−Stefan equations. This formulation is able to describe the diffusion process in different systems, such as, for instance, bulk diffusion (in the gas, liquid, and solid phase) and diffusion in microporous materials (membranes, zeolites, nanotubes, etc.). The Maxwell−Stefan equations can be solved analytically (only in special cases) or by numerical approaches. Different numerical strategies have been previously presented, but the number of diffusing species is normally restricted, with only few exceptions, to three in bulk diffusion and to two in microporous systems, unless simplifications of the Maxwell−Stefan equations are considered. In the literature, a large effort has been devoted to the derivation of the analytic expression of the elements of the Fick-like diffusion matrix and therefore to the symbolic inversion of a square matrix with dimensions n × n (n being the number of independent components). This step, which can be easily performed for n = 2 and remains reasonable for n = 3, becomes rapidly very complex in problems with a large number of components. This paper addresses the problem of the numerical resolution of the Maxwell−Stefan equations in the transient regime for a one-dimensional system with a generic number of components, avoiding the definition of the analytic expression of the elements of the Fick-like diffusion matrix. To this aim, two approaches have been implemented in a computational code; the first is the simple finite difference second-order accurate in time Crank−Nicolson scheme for which the full mathematical derivation and the relevant final equations are reported. The second is based on the more accurate backward differentiation formulas, BDF, or Gear’s method (Shampine, L. F.; Gear, C. W. SIAM Rev. 1979, 21, 1.), as implemented in the Livermore solver for ordinary differential equations, LSODE (Hindmarsh, A. C. Serial Fortran Solvers for ODE Initial Value Problems, Technical Report; https://computation.llnl.gov/casc/odepack/odepack_ home.html (2006) .). Both methods have been applied to a series of specific problems, such as bulk diffusion of acetone and methanol through stagnant air, uptake of two components on a microporous material in a model system, and permeation across a microporous membrane in model systems, both with the aim to validate the method and to add new information to the comprehension of the peculiar behavior of these systems. The approach is validated by comparison with different published results and with analytic expressions for the steady-state concentration profiles or fluxes in particular systems. The possibility to treat a generic number of components (the limitation being essentially the computational power) is also tested, and results are reported on the permeation of a five component mixture through a membrane in a model system. It is worth noticing that the algorithm here reported can be applied also to the Fick formulation of the diffusion problem with concentration-dependent diffusion coefficients
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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